CompareInfo.LastIndexOf Metod

Definition

Namnområde:: System.Globalization

Sammansättningar:: mscorlib.dll, System.Globalization.dll

Sammansättning:: mscorlib.dll

Sammansättning:: System.Globalization.dll

Sammansättning:: netstandard.dll

Viktigt

En del information gäller för förhandsversionen av en produkt och kan komma att ändras avsevärt innan produkten blir allmänt tillgänglig. Microsoft lämnar inga garantier, uttryckliga eller underförstådda, avseende informationen som visas här.

Returnerar det nollbaserade indexet för den senaste förekomsten av ett värde i en sträng eller inom en del av det.

Överlagringar

Name	Description
LastIndexOf(String, Char, Int32, Int32, CompareOptions)	Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som innehåller det angivna antalet element och slutar vid det angivna indexet med det angivna CompareOptions värdet.
LastIndexOf(String, String, Int32, Int32)	Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som innehåller det angivna antalet element och slutar vid det angivna indexet.
LastIndexOf(String, String, Int32, Int32, CompareOptions)	Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som innehåller det angivna antalet element och slutar vid det angivna indexet med det angivna CompareOptions värdet.
LastIndexOf(String, String, Int32, CompareOptions)	Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som sträcker sig från början av strängen till det angivna indexet med det angivna CompareOptions värdet.
LastIndexOf(String, Char, Int32, Int32)	Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som innehåller det angivna antalet element och slutar vid det angivna indexet.
LastIndexOf(String, Char, Int32, CompareOptions)	Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som sträcker sig från början av strängen till det angivna indexet med det angivna CompareOptions värdet.
LastIndexOf(String, Char, CompareOptions)	Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i hela källsträngen med det angivna CompareOptions värdet.
LastIndexOf(String, String, CompareOptions)	Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i hela källsträngen med det angivna CompareOptions värdet.
LastIndexOf(String, Char, Int32)	Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som sträcker sig från början av strängen till det angivna indexet.
LastIndexOf(String, String)	Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i hela källsträngen.
LastIndexOf(String, Char)	Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i hela källsträngen.
LastIndexOf(String, String, Int32)	Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som sträcker sig från början av strängen till det angivna indexet.

LastIndexOf(String, Char, Int32, Int32, CompareOptions)

Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som innehåller det angivna antalet element och slutar vid det angivna indexet med det angivna CompareOptions värdet.

public:
 virtual int LastIndexOf(System::String ^ source, char value, int startIndex, int count, System::Globalization::CompareOptions options);

public virtual int LastIndexOf(string source, char value, int startIndex, int count, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * char * int * int * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * char * int * int * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As Char, startIndex As Integer, count As Integer, options As CompareOptions) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: Char

Tecknet som ska hittas i source.

startIndex: Int32

Det nollbaserade startindexet för bakåtsökningen.

count: Int32

Antalet element i avsnittet som ska sökas.

options: CompareOptions

Ett värde som definierar hur source och value ska jämföras. options är antingen uppräkningsvärdet Ordinaleller en bitvis kombination av ett eller flera av följande värden: IgnoreCase, IgnoreSymbols, IgnoreNonSpace, IgnoreWidthoch IgnoreKanaType.

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, i avsnittet som source innehåller det antal element som anges av count och som slutar vid startIndex, med hjälp av de angivna jämförelsealternativen, annars -1. Returnerar startIndex om value är ett okunnigt tecken.

Undantag

ArgumentNullException

source är null.

ArgumentOutOfRangeException

startIndex ligger utanför intervallet för giltiga index för source.

-eller-

count är mindre än noll.

-eller-

startIndex och count ange inte ett giltigt avsnitt i source.

ArgumentException

options innehåller ett ogiltigt CompareOptions värde.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng inom en del av en sträng.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 8;
      // iL is the length of the substring.
      int iL = 18;
      // myT1 and myT2 are the strings used for padding.
      String myT1 = new String( '-', iS );
      String myT2;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

Original      : Is AE or ae the same as Æ or æ?
No options    : -------- ae the same as Æ -----
           AE :                         b
           ae :          b
            Æ :                         b
            æ :          b
Ordinal       : -------- ae the same as Æ -----
           AE :
           ae :          b
            Æ :                         b
            æ :
IgnoreCase    : -------- ae the same as Æ -----
           AE :          f              l
           ae :          f              l
            Æ :          f              l
            æ :          f              l

Original      : Is U" or u" the same as Ü or ü?
No options    : -------- u" the same as Ü -----
           U" :                         b
           u" :          b
            Ü :                         b
            ü :          b
Ordinal       : -------- u" the same as Ü -----
           U" :
           u" :          b
            Ü :                         b
            ü :
IgnoreCase    : -------- u" the same as Ü -----
           U" :          f              l
           u" :          f              l
            Ü :          f              l
            ü :          f              l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 8
      ' iL is the length of the substring.
      Dim iL As Integer = 18
      ' myT1 and myT2 are the strings used for padding.
      Dim myT1 As New [String]("-"c, [iS])
      Dim myT2 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------- ae the same as Æ -----
'           AE :                         b
'           ae :          b
'            Æ :                         b
'            æ :          b
'Ordinal       : -------- ae the same as Æ -----
'           AE :
'           ae :          b
'            Æ :                         b
'            æ :
'IgnoreCase    : -------- ae the same as Æ -----
'           AE :          f              l
'           ae :          f              l
'            Æ :          f              l
'            æ :          f              l
'
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------- u" the same as Ü -----
'           U" :                         b
'           u" :          b
'            Ü :                         b
'            ü :          b
'Ordinal       : -------- u" the same as Ü -----
'           U" :
'           u" :          b
'            Ü :                         b
'            ü :
'IgnoreCase    : -------- u" the same as Ü -----
'           U" :          f              l
'           u" :          f              l
'            Ü :          f              l
'            ü :          f              l

Kommentarer

Källsträngen söks bakåt från startIndex och med och slutar på startIndex - count + 1.

Värdena CompareOptions.NumericOrdering och CompareOptions.StringSort är inte giltiga för den här metoden.

Om options inte innehåller värdet utför den här överlagringen Ordinal en kulturkänslig sökning. Om tecknet är ett Unicode-värde som representerar ett förkomponerat tecken, till exempel ligaturen "Æ" (U+00C6), kan det anses motsvara alla förekomster av dess komponenter i rätt sekvens, till exempel "AE" (U+0041, U+0045), beroende på kulturen. Om options inkluderar värdet Ordinal utför den här överbelastningen en ordningstalssökning (kulturokänslig). Ett tecken anses vara likvärdigt med ett annat tecken endast om Unicode-värdena är desamma. Överlagringar av String.LastIndexOf sökningen efter ett tecken utför en ordningstalssökning, medan de som söker efter en sträng utför en kulturkänslig sökning.

Note

När det är möjligt bör du anropa metoder för strängjämförelse som har en parameter av typen CompareOptions för att ange vilken typ av jämförelse som förväntas. Som en allmän regel använder du språkalternativ (med den aktuella kulturen) för att jämföra strängar som visas i användargränssnittet och ange CompareOptions.Ordinal eller CompareOptions.OrdinalIgnoreCase för säkerhetsjämförelser.

Anteckningar till anropare

Teckenuppsättningar innehåller okunniga tecken, som är tecken som inte beaktas när du utför en språklig eller kulturkänslig sortering. I en kulturkänslig sökning, om value är ett okunnigt tecken, motsvarar resultatet att söka med det tecknet borttaget. I det här fallet LastIndexOf(String, Char, Int32, Int32, CompareOptions) returnerar startIndexmetoden alltid , vilket är teckenpositionen där sökningen börjar. I följande exempel LastIndexOf(String, Char, Int32, Int32, CompareOptions) används metoden för att hitta ett mjukt bindestreck (U+00AD) som föregår det sista "m" i två strängar. Endast en av strängarna innehåller ett mjukt bindestreck. I båda fallen, eftersom det mjuka bindestrecket är ett okunnigt tecken, returnerar en kulturkänslig sökning indexpositionen för "m", vilket är värdet för startIndex. En ordningssökning hittar dock det mjuka bindestrecket i en sträng och rapporterar att det saknas från den andra strängen.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      int position = 0;

      // Find the index of the soft hyphen using culture-sensitive comparison.
      position = ci.LastIndexOf(s1, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', position,
                           position + 1, CompareOptions.IgnoreCase));

      position = ci.LastIndexOf(s2, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', position,
                           position + 1, CompareOptions.IgnoreCase));

      // Find the index of the soft hyphen using ordinal comparison.
      position = ci.LastIndexOf(s1, 'm');
      Console.WriteLine("'m' at position {0}", position, CompareOptions.Ordinal);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', position,
                           position + 1, CompareOptions.Ordinal));

      position = ci.LastIndexOf(s2, 'm');
      Console.WriteLine("'m' at position {0}", position, CompareOptions.Ordinal);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', position,
                           position + 1, CompareOptions.Ordinal));
   }
}
// The example displays the following output:
//       'm' at position 4
//       4
//       'm' at position 3
//       3
//       'm' at position 4
//       3
//       'm' at position 3
//       -1

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim softHyphen As Char = ChrW(&h00AD)
      Dim position As Integer
      
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      ' Find the index of the soft hyphen using culture-sensitive comparison.
      position = ci.LastIndexOf(s1, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen, position, _
                           position + 1, CompareOptions.IgnoreCase))
      End If
      
      position = ci.LastIndexOf(s2, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen, position, _
                           position + 1, CompareOptions.IgnoreCase))
      End If  
       
      ' Find the index of the soft hyphen using ordinal comparison.
      position = ci.LastIndexOf(s1, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen, position, _
                           position + 1, CompareOptions.Ordinal))
      End If
      
      position = ci.LastIndexOf(s2, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen, position, _
                           position + 1, CompareOptions.Ordinal))
      End If   
   End Sub
End Module
' The example displays the following output:
'       'm' at position 4
'       4
'       'm' at position 3
'       3
'       'm' at position 4
'       3
'       'm' at position 3
'       -1

Se även

Gäller för

LastIndexOf(String, String, Int32, Int32)

Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som innehåller det angivna antalet element och slutar vid det angivna indexet.

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, int count);

public virtual int LastIndexOf(string source, string value, int startIndex, int count);

abstract member LastIndexOf : string * string * int * int -> int
override this.LastIndexOf : string * string * int * int -> int

Public Overridable Function LastIndexOf (source As String, value As String, startIndex As Integer, count As Integer) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: String

Strängen som ska hittas i source.

startIndex: Int32

Det nollbaserade startindexet för bakåtsökningen.

count: Int32

Antalet element i avsnittet som ska sökas.

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, i avsnittet som source innehåller det antal element som anges av count och som slutar vid startIndex, annars -1. Returnerar startIndex om value är ett okunnigt tecken.

Undantag

ArgumentNullException

source är null.

-eller-

value är null.

ArgumentOutOfRangeException

startIndex ligger utanför intervallet för giltiga index för source.

-eller-

count är mindre än noll.

-eller-

startIndex och count ange inte ett giltigt avsnitt i source.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng inom en del av en sträng.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 8;
      // iL is the length of the substring.
      int iL = 18;
      // myT1 and myT2 are the strings used for padding.
      String myT1 = new String( '-', iS );
      String myT2;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

Original      : Is AE or ae the same as Æ or æ?
No options    : -------- ae the same as Æ -----
           AE :                         b
           ae :          b
            Æ :                         b
            æ :          b
Ordinal       : -------- ae the same as Æ -----
           AE :
           ae :          b
            Æ :                         b
            æ :
IgnoreCase    : -------- ae the same as Æ -----
           AE :          f              l
           ae :          f              l
            Æ :          f              l
            æ :          f              l

Original      : Is U" or u" the same as Ü or ü?
No options    : -------- u" the same as Ü -----
           U" :                         b
           u" :          b
            Ü :                         b
            ü :          b
Ordinal       : -------- u" the same as Ü -----
           U" :
           u" :          b
            Ü :                         b
            ü :
IgnoreCase    : -------- u" the same as Ü -----
           U" :          f              l
           u" :          f              l
            Ü :          f              l
            ü :          f              l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 8
      ' iL is the length of the substring.
      Dim iL As Integer = 18
      ' myT1 and myT2 are the strings used for padding.
      Dim myT1 As New [String]("-"c, [iS])
      Dim myT2 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------- ae the same as Æ -----
'           AE :                         b
'           ae :          b
'            Æ :                         b
'            æ :          b
'Ordinal       : -------- ae the same as Æ -----
'           AE :
'           ae :          b
'            Æ :                         b
'            æ :
'IgnoreCase    : -------- ae the same as Æ -----
'           AE :          f              l
'           ae :          f              l
'            Æ :          f              l
'            æ :          f              l
'
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------- u" the same as Ü -----
'           U" :                         b
'           u" :          b
'            Ü :                         b
'            ü :          b
'Ordinal       : -------- u" the same as Ü -----
'           U" :
'           u" :          b
'            Ü :                         b
'            ü :
'IgnoreCase    : -------- u" the same as Ü -----
'           U" :          f              l
'           u" :          f              l
'            Ü :          f              l
'            ü :          f              l

Kommentarer

Källsträngen söks bakåt från startIndex och med och slutar på startIndex - count + 1.

Den här överlagringen utför en kulturkänslig sökning. Ett Unicode-värde som representerar ett förkomponerat tecken, till exempel ligaturen "Æ" (U+00C6), kan anses motsvara alla förekomster av tecknets komponenter i rätt sekvens, till exempel "AE" (U+0041, U+0045), beroende på kulturen. Om du vill utföra en ordningstalssökning (kulturokänslig) där Unicode-värdena jämförs bör du anropa en av de överlagringar som har en parameter av typen CompareOptions och använda Ordinal värdet.

Note

Anteckningar till anropare

I följande exempel LastIndexOf(String, String, Int32, Int32) används metoden för att hitta positionen för ett mjukt bindestreck (U+00AD) följt av ett "m" i de tre tecken som föregår det sista "m" av två strängar. Endast en av strängarna innehåller den delsträng som krävs. I båda fallen, eftersom det mjuka bindestrecket är ett okunnigt tecken, returnerar metoden indexet "m" i strängen när den utför en kulturkänslig jämförelse. Observera att när det gäller den första strängen, som innehåller det mjuka bindestrecket följt av ett "m", returnerar metoden inte indexet för det mjuka bindestrecket utan returnerar i stället indexet för "m".

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string searchString = "\u00ADm";
      string s1 = "ani\u00ADmal" ;
      string s2 = "animal";
      int position;

      position = ci.LastIndexOf(s1, 'm');
      if (position >= 0) {
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, 3, CompareOptions.None));
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, 3, CompareOptions.Ordinal));
      }

      position = ci.LastIndexOf(s2, 'm');
      if (position >= 0) {
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, 3, CompareOptions.None));
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, 3, CompareOptions.Ordinal));
      }
   }
}
// The example displays the following output:
//       4
//       3
//       3
//       -1

Imports System.Globalization

Public Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo

      Dim searchString As String = ChrW(&h00AD) + "m"
      Dim s1 As String = "ani" + ChrW(&h00AD) + "mal" 
      Dim s2 As String = "animal"
      Dim position As Integer

      position = ci.LastIndexOf(s1, "m"c)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, 3, CompareOptions.None))
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, 3, CompareOptions.Ordinal))
      End If
      
      position = ci.LastIndexOf(s2, "m"c)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, 3, CompareOptions.None))
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, 3, CompareOptions.Ordinal))
      End If
   End Sub
End Module
' The example displays the following output:
'       4
'       3
'       3
'       -1

Se även

IndexOf(String, Char)

Gäller för

LastIndexOf(String, String, Int32, Int32, CompareOptions)

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, int count, System::Globalization::CompareOptions options);

public virtual int LastIndexOf(string source, string value, int startIndex, int count, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * string * int * int * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * string * int * int * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As String, startIndex As Integer, count As Integer, options As CompareOptions) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: String

Strängen som ska hittas i source.

startIndex: Int32

Det nollbaserade startindexet för bakåtsökningen.

count: Int32

Antalet element i avsnittet som ska sökas.

options: CompareOptions

Returer

Int32

Undantag

ArgumentNullException

source är null.

-eller-

value är null.

ArgumentOutOfRangeException

startIndex ligger utanför intervallet för giltiga index för source.

-eller-

count är mindre än noll.

-eller-

startIndex och count ange inte ett giltigt avsnitt i source.

ArgumentException

options innehåller ett ogiltigt CompareOptions värde.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng inom en del av en sträng.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 8;
      // iL is the length of the substring.
      int iL = 18;
      // myT1 and myT2 are the strings used for padding.
      String myT1 = new String( '-', iS );
      String myT2;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

Original      : Is AE or ae the same as Æ or æ?
No options    : -------- ae the same as Æ -----
           AE :                         b
           ae :          b
            Æ :                         b
            æ :          b
Ordinal       : -------- ae the same as Æ -----
           AE :
           ae :          b
            Æ :                         b
            æ :
IgnoreCase    : -------- ae the same as Æ -----
           AE :          f              l
           ae :          f              l
            Æ :          f              l
            æ :          f              l

Original      : Is U" or u" the same as Ü or ü?
No options    : -------- u" the same as Ü -----
           U" :                         b
           u" :          b
            Ü :                         b
            ü :          b
Ordinal       : -------- u" the same as Ü -----
           U" :
           u" :          b
            Ü :                         b
            ü :
IgnoreCase    : -------- u" the same as Ü -----
           U" :          f              l
           u" :          f              l
            Ü :          f              l
            ü :          f              l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 8
      ' iL is the length of the substring.
      Dim iL As Integer = 18
      ' myT1 and myT2 are the strings used for padding.
      Dim myT1 As New [String]("-"c, [iS])
      Dim myT2 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------- ae the same as Æ -----
'           AE :                         b
'           ae :          b
'            Æ :                         b
'            æ :          b
'Ordinal       : -------- ae the same as Æ -----
'           AE :
'           ae :          b
'            Æ :                         b
'            æ :
'IgnoreCase    : -------- ae the same as Æ -----
'           AE :          f              l
'           ae :          f              l
'            Æ :          f              l
'            æ :          f              l
'
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------- u" the same as Ü -----
'           U" :                         b
'           u" :          b
'            Ü :                         b
'            ü :          b
'Ordinal       : -------- u" the same as Ü -----
'           U" :
'           u" :          b
'            Ü :                         b
'            ü :
'IgnoreCase    : -------- u" the same as Ü -----
'           U" :          f              l
'           u" :          f              l
'            Ü :          f              l
'            ü :          f              l

Kommentarer

Källsträngen söks bakåt från startIndex och med och slutar på startIndex - count + 1.

Värdena CompareOptions.NumericOrdering och CompareOptions.StringSort är inte giltiga för den här metoden.

Om options inte innehåller värdet utför den här överlagringen Ordinal en kulturkänslig sökning. Ett Unicode-värde som representerar ett förkomponerat tecken, till exempel ligaturen "Æ" (U+00C6), kan anses motsvara alla förekomster av tecknets komponenter i rätt sekvens, till exempel "AE" (U+0041, U+0045), beroende på kulturen. Om options inkluderar värdet Ordinal utför den här överbelastningen en ordningstalssökning (kulturokänslig) där Unicode-värdena jämförs.

Note

Anteckningar till anropare

I följande exempel LastIndexOf(String, String, Int32, Int32, CompareOptions) används metoden för att hitta positionen för ett mjukt bindestreck (U+00AD) följt av ett "m" i alla utom den första teckenpositionen före det sista "m" i två strängar. Endast en av strängarna innehåller den delsträng som krävs. I båda fallen, eftersom det mjuka bindestrecket är ett okunnigt tecken, returnerar metoden indexet "m" i strängen när den utför en kulturkänslig jämförelse. När den utför en ordningsjämförelse hittar den dock endast delsträngen i den första strängen. Observera att när det gäller den första strängen, som innehåller det mjuka bindestrecket följt av ett "m", returnerar metoden inte indexet för det mjuka bindestrecket, utan returnerar i stället indexet för "m" när den utför en kulturkänslig jämförelse. Metoden returnerar indexet för det mjuka bindestrecket i den första strängen endast när den utför en ordningsjämförelse.

Imports System.Globalization

Public Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo

      Dim searchString As String = ChrW(&h00AD) + "m"
      Dim s1 As String = "ani" + ChrW(&h00AD) + "m" 
      Dim s2 As String = "animal"
      Dim position As Integer

      position = ci.LastIndexOf(s1, "m"c)
      If position >= 1 Then
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, position, CompareOptions.None))
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, position, CompareOptions.Ordinal))
      End If      
      
      position = ci.LastIndexOf(s2, "m"c)
      If position >= 1 Then 
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, position, CompareOptions.None))
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, position, CompareOptions.Ordinal))
      End If
   End Sub
End Module
' The example displays the following output:
'       4
'       3
'       3
'       -1

Se även

Gäller för

LastIndexOf(String, String, Int32, CompareOptions)

Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som sträcker sig från början av strängen till det angivna indexet med det angivna CompareOptions värdet.

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, System::Globalization::CompareOptions options);

public virtual int LastIndexOf(string source, string value, int startIndex, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * string * int * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * string * int * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As String, startIndex As Integer, options As CompareOptions) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: String

Strängen som ska hittas i source.

startIndex: Int32

Det nollbaserade startindexet för bakåtsökningen.

options: CompareOptions

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, i avsnittet som source sträcker sig från början av source till startIndex, med de angivna jämförelsealternativen, annars -1. Returnerar startIndex om value är ett okunnigt tecken.

Undantag

ArgumentNullException

source är null.

-eller-

value är null.

ArgumentOutOfRangeException

startIndex ligger utanför intervallet för giltiga index för source.

ArgumentException

options innehåller ett ogiltigt CompareOptions värde.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng inom en del av en sträng. Observera att IndexOf och LastIndexOf söker i olika delar av strängen, även med samma startIndex parameter.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 20;
      // myT1 is the string used for padding.
      String myT1;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 20
      ' myT1 is the string used for padding.
      Dim myT1 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS]), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS]), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS]), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS]))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS]))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS]))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.Ordinal))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.Ordinal))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS]), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS]))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS]))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS]))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))
      
      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'IndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                              f
'            Æ :                         f
'            æ :                              f
'Ordinal       : -------------------- as Æ or æ?
'           AE :
'           ae :
'            Æ :                         f
'            æ :                              f
'IgnoreCase    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                         f
'            Æ :                         f
'            æ :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :    l
'            æ :          l
'Ordinal       : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :
'            æ :
'IgnoreCase    : Is AE or ae the same ----------
'           AE :          l
'           ae :          l
'            Æ :          l
'            æ :          l
'
'IndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                              f
'            Ü :                         f
'            ü :                              f
'Ordinal       : -------------------- as Ü or ü?
'           U" :
'           u" :
'            Ü :                         f
'            ü :                              f
'IgnoreCase    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                         f
'            Ü :                         f
'            ü :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :    l
'            ü :          l
'Ordinal       : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :
'            ü :
'IgnoreCase    : Is U" or u" the same ----------
'           U" :          l
'           u" :          l
'            Ü :          l
'            ü :          l

Kommentarer

Källsträngen söks bakåt med början och startIndex slutar i början av strängen.

Värdena CompareOptions.NumericOrdering och CompareOptions.StringSort är inte giltiga för den här metoden.

Note

Anteckningar till anropare

I följande exempel LastIndexOf(String, String, Int32, CompareOptions) används metoden för att hitta positionen för ett mjukt bindestreck (U+00AD) följt av ett "m", som börjar med det sista "m" i två strängar. Endast en av strängarna innehåller den delsträng som krävs. I båda fallen, eftersom det mjuka bindestrecket är ett okunnigt tecken, returnerar metoden indexet "m" i strängen när den utför en kulturkänslig jämförelse. Observera att när det gäller den första strängen, som innehåller det mjuka bindestrecket följt av ett "m", returnerar metoden inte indexet för det mjuka bindestrecket utan returnerar i stället indexet för "m". Metoden returnerar indexet för det mjuka bindestrecket i den första strängen endast när den utför en ordningsjämförelse.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string searchString = "\u00ADm";
      string s1 = "ani\u00ADmal" ;
      string s2 = "animal";
      int position;

      position = ci.LastIndexOf(s1, 'm');
      if (position >= 0) {
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, CompareOptions.None));
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, CompareOptions.Ordinal));
      }

      position = ci.LastIndexOf(s2, 'm');
      if (position >= 0) {
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, CompareOptions.None));
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, CompareOptions.Ordinal));
      }
   }
}
// The example displays the following output:
//       4
//       3
//       3
//       -1

Imports System.Globalization

Public Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo

      Dim searchString As String = ChrW(&h00AD) + "m"
      Dim s1 As String = "ani" + ChrW(&h00AD) + "mal" 
      Dim s2 As String = "animal"
      Dim position As Integer

      position = ci.LastIndexOf(s1, "m"c)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, CompareOptions.None))
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, CompareOptions.Ordinal))
      End If
      
      position = ci.LastIndexOf(s2, "m"c)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, CompareOptions.None))
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, CompareOptions.Ordinal))
      End If
   End Sub
End Module
' The example displays the following output:
'       4
'       3
'       3
'       -1

Se även

Gäller för

LastIndexOf(String, Char, Int32, Int32)

public:
 virtual int LastIndexOf(System::String ^ source, char value, int startIndex, int count);

public virtual int LastIndexOf(string source, char value, int startIndex, int count);

abstract member LastIndexOf : string * char * int * int -> int
override this.LastIndexOf : string * char * int * int -> int

Public Overridable Function LastIndexOf (source As String, value As Char, startIndex As Integer, count As Integer) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: Char

Tecknet som ska hittas i source.

startIndex: Int32

Det nollbaserade startindexet för bakåtsökningen.

count: Int32

Antalet element i avsnittet som ska sökas.

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, i avsnittet som source innehåller det antal element som anges av count och som slutar vid startIndex, annars -1. Returnerar startIndex om value är ett okunnigt tecken.

Undantag

ArgumentNullException

source är null.

ArgumentOutOfRangeException

startIndex ligger utanför intervallet för giltiga index för source.

-eller-

count är mindre än noll.

-eller-

startIndex och count ange inte ett giltigt avsnitt i source.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng inom en del av en sträng.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 8;
      // iL is the length of the substring.
      int iL = 18;
      // myT1 and myT2 are the strings used for padding.
      String myT1 = new String( '-', iS );
      String myT2;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

Original      : Is AE or ae the same as Æ or æ?
No options    : -------- ae the same as Æ -----
           AE :                         b
           ae :          b
            Æ :                         b
            æ :          b
Ordinal       : -------- ae the same as Æ -----
           AE :
           ae :          b
            Æ :                         b
            æ :
IgnoreCase    : -------- ae the same as Æ -----
           AE :          f              l
           ae :          f              l
            Æ :          f              l
            æ :          f              l

Original      : Is U" or u" the same as Ü or ü?
No options    : -------- u" the same as Ü -----
           U" :                         b
           u" :          b
            Ü :                         b
            ü :          b
Ordinal       : -------- u" the same as Ü -----
           U" :
           u" :          b
            Ü :                         b
            ü :
IgnoreCase    : -------- u" the same as Ü -----
           U" :          f              l
           u" :          f              l
            Ü :          f              l
            ü :          f              l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 8
      ' iL is the length of the substring.
      Dim iL As Integer = 18
      ' myT1 and myT2 are the strings used for padding.
      Dim myT1 As New [String]("-"c, [iS])
      Dim myT2 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------- ae the same as Æ -----
'           AE :                         b
'           ae :          b
'            Æ :                         b
'            æ :          b
'Ordinal       : -------- ae the same as Æ -----
'           AE :
'           ae :          b
'            Æ :                         b
'            æ :
'IgnoreCase    : -------- ae the same as Æ -----
'           AE :          f              l
'           ae :          f              l
'            Æ :          f              l
'            æ :          f              l
'
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------- u" the same as Ü -----
'           U" :                         b
'           u" :          b
'            Ü :                         b
'            ü :          b
'Ordinal       : -------- u" the same as Ü -----
'           U" :
'           u" :          b
'            Ü :                         b
'            ü :
'IgnoreCase    : -------- u" the same as Ü -----
'           U" :          f              l
'           u" :          f              l
'            Ü :          f              l
'            ü :          f              l

Kommentarer

Källsträngen söks bakåt från startIndex och med och slutar på startIndex - count + 1.

Den här överlagringen utför en kulturkänslig sökning. Om tecknet är ett Unicode-värde som representerar ett förkomponerat tecken, till exempel ligaturen "Æ" (U+00C6), kan det anses motsvara alla förekomster av dess komponenter i rätt sekvens, till exempel "AE" (U+0041, U+0045), beroende på kulturen. Om du vill utföra en ordningsfråga (kulturokänslig) sökning, där ett tecken endast anses motsvara ett annat tecken om Unicode-värdena är desamma, bör du anropa en av de överlagringar som har en parameter av typen CompareOptions och använda Ordinal värdet. Överlagringar av String.LastIndexOf sökningen efter ett tecken utför en ordningstalssökning, medan de som söker efter en sträng utför en kulturkänslig sökning.

Note

Anteckningar till anropare

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      int position = 0;

      // Find the index of the soft hyphen.
      position = ci.IndexOf(s1, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', position, position + 1));

      position = ci.IndexOf(s2, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', position, position + 1));
   }
}
// The example displays the following output:
//       'm' at position 4
//       4
//       'm' at position 3
//       3

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim position As Integer
      Dim softHyphen As Char = ChrW(&h00AD)
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      ' Find the index of the soft hyphen.
      position = ci.IndexOf(s1, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen, position, position + 1))
      End If
      
      position = ci.IndexOf(s2, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen, position, position + 1))
      End If   
   End Sub
End Module
' The example displays the following output:
'       'm' at position 4
'       4
'       'm' at position 3
'       3

Se även

IndexOf(String, Char)

Gäller för

LastIndexOf(String, Char, Int32, CompareOptions)

Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i avsnittet i källsträngen som sträcker sig från början av strängen till det angivna indexet med det angivna CompareOptions värdet.

public:
 virtual int LastIndexOf(System::String ^ source, char value, int startIndex, System::Globalization::CompareOptions options);

public virtual int LastIndexOf(string source, char value, int startIndex, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * char * int * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * char * int * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As Char, startIndex As Integer, options As CompareOptions) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: Char

Tecknet som ska hittas i source.

startIndex: Int32

Det nollbaserade startindexet för bakåtsökningen.

options: CompareOptions

Returer

Int32

Undantag

ArgumentNullException

source är null.

ArgumentOutOfRangeException

startIndex ligger utanför intervallet för giltiga index för source.

ArgumentException

options innehåller ett ogiltigt CompareOptions värde.

Exempel

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 20;
      // myT1 is the string used for padding.
      String myT1;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 20
      ' myT1 is the string used for padding.
      Dim myT1 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS]), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS]), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS]), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS]))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS]))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS]))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.Ordinal))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.Ordinal))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS]), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS]))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS]))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS]))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))
      
      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'IndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                              f
'            Æ :                         f
'            æ :                              f
'Ordinal       : -------------------- as Æ or æ?
'           AE :
'           ae :
'            Æ :                         f
'            æ :                              f
'IgnoreCase    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                         f
'            Æ :                         f
'            æ :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :    l
'            æ :          l
'Ordinal       : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :
'            æ :
'IgnoreCase    : Is AE or ae the same ----------
'           AE :          l
'           ae :          l
'            Æ :          l
'            æ :          l
'
'IndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                              f
'            Ü :                         f
'            ü :                              f
'Ordinal       : -------------------- as Ü or ü?
'           U" :
'           u" :
'            Ü :                         f
'            ü :                              f
'IgnoreCase    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                         f
'            Ü :                         f
'            ü :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :    l
'            ü :          l
'Ordinal       : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :
'            ü :
'IgnoreCase    : Is U" or u" the same ----------
'           U" :          l
'           u" :          l
'            Ü :          l
'            ü :          l

Kommentarer

Källsträngen söks bakåt med början och startIndex slutar i början av strängen.

Värdena CompareOptions.NumericOrdering och CompareOptions.StringSort är inte giltiga för den här metoden.

Note

Anteckningar till anropare

Teckenuppsättningar innehåller okunniga tecken, som är tecken som inte beaktas när du utför en språklig eller kulturkänslig sortering. I en kulturkänslig sökning, om value är ett okunnigt tecken, motsvarar resultatet att söka med det tecknet borttaget. I det här fallet LastIndexOf(String, Char, Int32, CompareOptions) returnerar startIndexmetoden alltid , vilket är teckenpositionen där sökningen börjar. I följande exempel LastIndexOf(String, Char, Int32, CompareOptions) används metoden för att hitta ett mjukt bindestreck (U+00AD) som föregår det sista "m" i två strängar. Endast en av strängarna innehåller ett mjukt bindestreck. I båda fallen, eftersom det mjuka bindestrecket är ett okunnigt tecken, returnerar en kulturkänslig sökning indexpositionen för "m". En ordningssökning hittar dock det mjuka bindestrecket i en sträng och rapporterar att det saknas från den andra strängen.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      int position = 0;

      // Find the index of the soft hyphen using culture-sensitive comparison.
      position = ci.LastIndexOf(s1, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', position, CompareOptions.IgnoreCase));

      position = ci.LastIndexOf(s2, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', position, CompareOptions.IgnoreCase));

      // Find the index of the soft hyphen using ordinal comparison.
      position = ci.LastIndexOf(s1, 'm');
      Console.WriteLine("'m' at position {0}", position, CompareOptions.Ordinal);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', position, CompareOptions.Ordinal));

      position = ci.LastIndexOf(s2, 'm');
      Console.WriteLine("'m' at position {0}", position, CompareOptions.Ordinal);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', position, CompareOptions.Ordinal));
   }
}
// The example displays the following output:
//       'm' at position 4
//       4
//       'm' at position 3
//       3
//       'm' at position 4
//       3
//       'm' at position 3
//       -1

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim softHyphen As Char = ChrW(&h00AD)
      Dim position As Integer
      
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      ' Find the index of the soft hyphen using culture-sensitive comparison.
      position = ci.LastIndexOf(s1, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen, position, CompareOptions.IgnoreCase))
      End If
      
      position = ci.LastIndexOf(s2, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen, position, CompareOptions.IgnoreCase))
      End If  
       
      ' Find the index of the soft hyphen using ordinal comparison.
      position = ci.LastIndexOf(s1, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen, position, CompareOptions.Ordinal))
      End If
      
      position = ci.LastIndexOf(s2, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen, position, CompareOptions.Ordinal))
      End If   
   End Sub
End Module
' The example displays the following output:
'       'm' at position 4
'       4
'       'm' at position 3
'       3
'       'm' at position 4
'       3
'       'm' at position 3
'       -1

Se även

Gäller för

LastIndexOf(String, Char, CompareOptions)

Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i hela källsträngen med det angivna CompareOptions värdet.

public:
 virtual int LastIndexOf(System::String ^ source, char value, System::Globalization::CompareOptions options);

public virtual int LastIndexOf(string source, char value, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * char * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * char * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As Char, options As CompareOptions) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: Char

Tecknet som ska hittas i source.

options: CompareOptions

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, inom source, med hjälp av de angivna jämförelsealternativen, annars -1.

Undantag

ArgumentNullException

source är null.

ArgumentException

options innehåller ett ogiltigt CompareOptions värde.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng i en sträng.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE" ), myComp.LastIndexOf( myStr, "AE" ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae" ), myComp.LastIndexOf( myStr, "ae" ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ' ), myComp.LastIndexOf( myStr, 'Æ' ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ' ), myComp.LastIndexOf( myStr, 'æ' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308" ), myComp.LastIndexOf( myStr, "U\u0308" ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308" ), myComp.LastIndexOf( myStr, "u\u0308" ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü' ), myComp.LastIndexOf( myStr, 'Ü' ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü' ), myComp.LastIndexOf( myStr, 'ü' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE"), myComp.LastIndexOf(myStr, "AE"))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae"), myComp.LastIndexOf(myStr, "ae"))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c), myComp.LastIndexOf(myStr, "Æ"c))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c), myComp.LastIndexOf(myStr, "æ"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308)))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308)))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c), myComp.LastIndexOf(myStr, "Ü"c))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c), myComp.LastIndexOf(myStr, "ü"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 
         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'No options    : Is AE or ae the same as Æ or æ?
'           AE :    f                    l
'           ae :          f                   l
'            Æ :    f                    l
'            æ :          f                   l
'Ordinal       : Is AE or ae the same as Æ or æ?
'           AE :    b
'           ae :          b
'            Æ :                         b
'            æ :                              b
'IgnoreCase    : Is AE or ae the same as Æ or æ?
'           AE :    f                         l
'           ae :    f                         l
'            Æ :    f                         l
'            æ :    f                         l
'
'No options    : Is U" or u" the same as Ü or ü?
'           U" :    f                    l
'           u" :          f                   l
'            Ü :    f                    l
'            ü :          f                   l
'Ordinal       : Is U" or u" the same as Ü or ü?
'           U" :    b
'           u" :          b
'            Ü :                         b
'            ü :                              b
'IgnoreCase    : Is U" or u" the same as Ü or ü?
'           U" :    f                         l
'           u" :    f                         l
'            Ü :    f                         l
'            ü :    f                         l

Kommentarer

Källsträngen söks bakåt med början i slutet av strängen och slutar i början av strängen.

Värdena CompareOptions.NumericOrdering och CompareOptions.StringSort är inte giltiga för den här metoden.

Note

Anteckningar till anropare

Teckenuppsättningar innehåller okunniga tecken, som är tecken som inte beaktas när du utför en språklig eller kulturkänslig sortering. I en kulturkänslig sökning, om value är ett okunnigt tecken, motsvarar resultatet att söka med det tecknet borttaget. I det här fallet LastIndexOf(String, Char, CompareOptions) returnerar metoden alltid den sista teckenpositionen i source för att indikera att matchningen hittas i slutet av source. I följande exempel LastIndexOf(String, Char, CompareOptions) används metoden för att söka efter ett mjukt bindestreck (U+00AD) i två strängar. Endast en av strängarna innehåller ett mjukt bindestreck. I båda fallen, eftersom det mjuka bindestrecket är ett okunnigt tecken, returnerar en kulturkänslig sökning den sista indexpositionen i källsträngen. En ordningssökning hittar däremot det mjuka bindestrecket i en sträng och rapporterar att det saknas från den andra strängen.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      // Find the last index of the soft hyphen using culture-sensitive comparison.
      Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', CompareOptions.IgnoreCase));
      Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', CompareOptions.IgnoreCase));

      // Find the last index of the soft hyphen using ordinal comparison.
      Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', CompareOptions.Ordinal));
      Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', CompareOptions.Ordinal));
   }
}
// The example displays the following output:
//       6
//       5
//       3
//       -1

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim softHyphen As Char = ChrW(&h00AD)
      
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      ' Find the last index of the soft hyphen using culture-sensitive comparison.
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen, CompareOptions.IgnoreCase))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen, CompareOptions.IgnoreCase))
      
      ' Find the last index of the soft hyphen using ordinal comparison.
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen, CompareOptions.Ordinal))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen, CompareOptions.Ordinal))
   End Sub
End Module
' The example displays the following output:
'       6
'       5
'       3
'       -1

Se även

Gäller för

LastIndexOf(String, String, CompareOptions)

Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i hela källsträngen med det angivna CompareOptions värdet.

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, System::Globalization::CompareOptions options);

public virtual int LastIndexOf(string source, string value, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * string * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * string * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As String, options As CompareOptions) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: String

Strängen som ska hittas i source.

options: CompareOptions

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, inom source, med hjälp av de angivna jämförelsealternativen, annars -1.

Undantag

ArgumentNullException

source är null.

-eller-

value är null.

ArgumentException

options innehåller ett ogiltigt CompareOptions värde.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng i en sträng.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE" ), myComp.LastIndexOf( myStr, "AE" ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae" ), myComp.LastIndexOf( myStr, "ae" ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ' ), myComp.LastIndexOf( myStr, 'Æ' ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ' ), myComp.LastIndexOf( myStr, 'æ' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308" ), myComp.LastIndexOf( myStr, "U\u0308" ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308" ), myComp.LastIndexOf( myStr, "u\u0308" ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü' ), myComp.LastIndexOf( myStr, 'Ü' ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü' ), myComp.LastIndexOf( myStr, 'ü' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE"), myComp.LastIndexOf(myStr, "AE"))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae"), myComp.LastIndexOf(myStr, "ae"))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c), myComp.LastIndexOf(myStr, "Æ"c))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c), myComp.LastIndexOf(myStr, "æ"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308)))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308)))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c), myComp.LastIndexOf(myStr, "Ü"c))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c), myComp.LastIndexOf(myStr, "ü"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 
         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'No options    : Is AE or ae the same as Æ or æ?
'           AE :    f                    l
'           ae :          f                   l
'            Æ :    f                    l
'            æ :          f                   l
'Ordinal       : Is AE or ae the same as Æ or æ?
'           AE :    b
'           ae :          b
'            Æ :                         b
'            æ :                              b
'IgnoreCase    : Is AE or ae the same as Æ or æ?
'           AE :    f                         l
'           ae :    f                         l
'            Æ :    f                         l
'            æ :    f                         l
'
'No options    : Is U" or u" the same as Ü or ü?
'           U" :    f                    l
'           u" :          f                   l
'            Ü :    f                    l
'            ü :          f                   l
'Ordinal       : Is U" or u" the same as Ü or ü?
'           U" :    b
'           u" :          b
'            Ü :                         b
'            ü :                              b
'IgnoreCase    : Is U" or u" the same as Ü or ü?
'           U" :    f                         l
'           u" :    f                         l
'            Ü :    f                         l
'            ü :    f                         l

Kommentarer

Källsträngen söks bakåt med början i slutet av strängen och slutar i början av strängen.

Värdena CompareOptions.NumericOrdering och CompareOptions.StringSort är inte giltiga för den här metoden.

Note

Anteckningar till anropare

Teckenuppsättningar innehåller okunniga tecken, som är tecken som inte beaktas när du utför en språklig eller kulturkänslig sortering. I en kulturkänslig sökning (dvs. om options den inte Ordinal är eller OrdinalIgnoreCase), om value den innehåller ett okunnigt tecken, motsvarar resultatet att söka med det tecknet borttaget. Om value endast består av ett eller flera okunniga tecken LastIndexOf(String, String, CompareOptions) returnerar sourcemetoden alltid .Length - 1, vilket representerar den sista indexpositionen i source. I följande exempel LastIndexOf(String, String, CompareOptions) används metoden för att hitta tre understrängar (ett mjukt bindestreck (U+00AD), ett mjukt bindestreck följt av "n" och ett mjukt bindestreck följt av "m") i två strängar. Endast en av strängarna innehåller ett mjukt bindestreck. Eftersom det mjuka bindestrecket är ett okunnigt tecken returnerar en kulturkänslig sökning samma värde som det skulle returnera om det mjuka bindestrecket inte ingick i söksträngen. En ordningssökning hittar dock det mjuka bindestrecket i en sträng och rapporterar att det saknas från den andra strängen.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      Console.WriteLine("Culture-sensitive comparison:");
      // Use culture-sensitive comparison to find the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, "\u00AD", CompareOptions.None));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00AD", CompareOptions.None));

      // Use culture-sensitive comparison to find the last soft hyphen followed by "n".
      Console.WriteLine(ci.LastIndexOf(s1, "\u00ADn", CompareOptions.None));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00ADn", CompareOptions.None));

      // Use culture-sensitive comparison to find the last soft hyphen followed by "m".
      Console.WriteLine(ci.LastIndexOf(s1, "\u00ADm", CompareOptions.None));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00ADm", CompareOptions.None));

      Console.WriteLine("Ordinal comparison:");
      // Use ordinal comparison to find the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, "\u00AD", CompareOptions.Ordinal));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00AD", CompareOptions.Ordinal));

      // Use ordinal comparison to find the last soft hyphen followed by "n".
      Console.WriteLine(ci.LastIndexOf(s1, "\u00ADn", CompareOptions.Ordinal));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00ADn", CompareOptions.Ordinal));

      // Use ordinal comparison to find the last soft hyphen followed by "m".
      Console.WriteLine(ci.LastIndexOf(s1, "\u00ADm", CompareOptions.Ordinal));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00ADm", CompareOptions.Ordinal));
   }
}
// The example displays the following output:
//       6
//       5
//       1
//       1
//       4
//       3
//       Ordinal comparison:
//       3
//       -1
//       -1
//       -1
//       3
//       -1

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim softHyphen As String = ChrW(&h00AD)
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      Console.WriteLine("Culture-sensitive comparison:")
      ' Use culture-sensitive comparison to find the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen, CompareOptions.None))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen, CompareOptions.None))
      
      ' Use culture-sensitive comparison to find the last soft hyphen followed by "n".
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen + "n", CompareOptions.None))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen + "n", CompareOptions.None))
      
      ' Use culture-sensitive comparison to find the last soft hyphen followed by "m".
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen + "m", CompareOptions.None))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen + "m", CompareOptions.None))
      
      Console.WriteLine("Ordinal comparison:")
      ' Use ordinal comparison to find the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen, CompareOptions.Ordinal))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen, CompareOptions.Ordinal))
      
      ' Use ordinal comparison to find the last soft hyphen followed by "n".
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen + "n", CompareOptions.Ordinal))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen + "n", CompareOptions.Ordinal))
      
      ' Use ordinal comparison to find the last soft hyphen followed by "m".
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen + "m", CompareOptions.Ordinal))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen + "m", CompareOptions.Ordinal))
   End Sub
End Module
' The example displays the following output:
'       6
'       5
'       1
'       1
'       4
'       3
'       Ordinal comparison:
'       3
'       -1
'       -1
'       -1
'       3
'       -1

Se även

Gäller för

LastIndexOf(String, Char, Int32)

public:
 virtual int LastIndexOf(System::String ^ source, char value, int startIndex);

public virtual int LastIndexOf(string source, char value, int startIndex);

abstract member LastIndexOf : string * char * int -> int
override this.LastIndexOf : string * char * int -> int

Public Overridable Function LastIndexOf (source As String, value As Char, startIndex As Integer) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: Char

Tecknet som ska hittas i source.

startIndex: Int32

Det nollbaserade startindexet för bakåtsökningen.

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, inom avsnittet i source det sträcker sig från början av source till startIndex, annars -1. Returnerar startIndex om value är ett okunnigt tecken.

Undantag

ArgumentNullException

source är null.

ArgumentOutOfRangeException

startIndex ligger utanför intervallet för giltiga index för source.

Exempel

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 20;
      // myT1 is the string used for padding.
      String myT1;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 20
      ' myT1 is the string used for padding.
      Dim myT1 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS]), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS]), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS]), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS]))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS]))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS]))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.Ordinal))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.Ordinal))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS]), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS]))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS]))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS]))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))
      
      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'IndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                              f
'            Æ :                         f
'            æ :                              f
'Ordinal       : -------------------- as Æ or æ?
'           AE :
'           ae :
'            Æ :                         f
'            æ :                              f
'IgnoreCase    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                         f
'            Æ :                         f
'            æ :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :    l
'            æ :          l
'Ordinal       : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :
'            æ :
'IgnoreCase    : Is AE or ae the same ----------
'           AE :          l
'           ae :          l
'            Æ :          l
'            æ :          l
'
'IndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                              f
'            Ü :                         f
'            ü :                              f
'Ordinal       : -------------------- as Ü or ü?
'           U" :
'           u" :
'            Ü :                         f
'            ü :                              f
'IgnoreCase    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                         f
'            Ü :                         f
'            ü :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :    l
'            ü :          l
'Ordinal       : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :
'            ü :
'IgnoreCase    : Is U" or u" the same ----------
'           U" :          l
'           u" :          l
'            Ü :          l
'            ü :          l

Kommentarer

Källsträngen söks bakåt med början och startIndex slutar i början av strängen.

Note

Anteckningar till anropare

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      int position = 0;

      // Find the last index of the soft hyphen.
      position = ci.LastIndexOf(s1, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', position));

      position = ci.LastIndexOf(s2, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', position));
   }
}
// The example displays the following output:
//       'm' at position 4
//       4
//       'm' at position 3

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim position As Integer
      Dim softHyphen As Char = ChrW(&h00AD)
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      ' Find the last index of the soft hyphen.
      position = ci.LastIndexOf(s1, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen, position))
      End If
      
      position = ci.LastIndexOf(s2, "m"c)
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen, position))
      End If   
   End Sub
End Module
' The example displays the following output:
'       'm' at position 4
'       4
'       'm' at position 3
'       3

Se även

IndexOf(String, Char)

Gäller för

LastIndexOf(String, String)

Söker efter den angivna delsträngen och returnerar det nollbaserade indexet för den senaste förekomsten i hela källsträngen.

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value);

public virtual int LastIndexOf(string source, string value);

abstract member LastIndexOf : string * string -> int
override this.LastIndexOf : string * string -> int

Public Overridable Function LastIndexOf (source As String, value As String) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: String

Strängen som ska hittas i source.

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, inom source; annars -1.

Undantag

ArgumentNullException

source är null.

-eller-

value är null.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng i en sträng.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE" ), myComp.LastIndexOf( myStr, "AE" ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae" ), myComp.LastIndexOf( myStr, "ae" ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ' ), myComp.LastIndexOf( myStr, 'Æ' ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ' ), myComp.LastIndexOf( myStr, 'æ' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308" ), myComp.LastIndexOf( myStr, "U\u0308" ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308" ), myComp.LastIndexOf( myStr, "u\u0308" ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü' ), myComp.LastIndexOf( myStr, 'Ü' ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü' ), myComp.LastIndexOf( myStr, 'ü' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE"), myComp.LastIndexOf(myStr, "AE"))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae"), myComp.LastIndexOf(myStr, "ae"))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c), myComp.LastIndexOf(myStr, "Æ"c))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c), myComp.LastIndexOf(myStr, "æ"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308)))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308)))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c), myComp.LastIndexOf(myStr, "Ü"c))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c), myComp.LastIndexOf(myStr, "ü"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 
         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'No options    : Is AE or ae the same as Æ or æ?
'           AE :    f                    l
'           ae :          f                   l
'            Æ :    f                    l
'            æ :          f                   l
'Ordinal       : Is AE or ae the same as Æ or æ?
'           AE :    b
'           ae :          b
'            Æ :                         b
'            æ :                              b
'IgnoreCase    : Is AE or ae the same as Æ or æ?
'           AE :    f                         l
'           ae :    f                         l
'            Æ :    f                         l
'            æ :    f                         l
'
'No options    : Is U" or u" the same as Ü or ü?
'           U" :    f                    l
'           u" :          f                   l
'            Ü :    f                    l
'            ü :          f                   l
'Ordinal       : Is U" or u" the same as Ü or ü?
'           U" :    b
'           u" :          b
'            Ü :                         b
'            ü :                              b
'IgnoreCase    : Is U" or u" the same as Ü or ü?
'           U" :    f                         l
'           u" :    f                         l
'            Ü :    f                         l
'            ü :    f                         l

Kommentarer

Källsträngen söks bakåt med början i slutet av strängen och slutar i början av strängen.

Note

Anteckningar till anropare

Teckenuppsättningar innehåller okunniga tecken, som är tecken som inte beaktas när du utför en språklig eller kulturkänslig sortering. I en kulturkänslig sökning, om value innehåller ett okunnigt tecken, motsvarar resultatet att söka med det tecknet borttaget. Om value endast består av ett eller flera okunniga tecken LastIndexOf(String, String) returnerar sourcemetoden alltid .Length - 1, vilket representerar den sista indexpositionen i source. I följande exempel LastIndexOf(String, String) används metoden för att hitta tre understrängar (ett mjukt bindestreck (U+00AD), ett mjukt bindestreck följt av "n" och ett mjukt bindestreck följt av "m") i två strängar. Endast en av strängarna innehåller ett mjukt bindestreck. I varje fall, eftersom det mjuka bindestrecket är ett okunnigt tecken, är resultatet detsamma som om det mjuka bindestrecket inte hade inkluderats i value. När du söker efter ett mjukt bindestreck returnerar metoden 6 och 5. Dessa värden motsvarar indexet för det sista tecknet i de två strängarna.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      // Find the index of the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, "\u00AD"));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00AD"));

      // Find the index of the last soft hyphen followed by "n".
      Console.WriteLine(ci.LastIndexOf(s1, "\u00ADn"));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00ADn"));

      // Find the index of the last soft hyphen followed by "m".
      Console.WriteLine(ci.LastIndexOf(s1, "\u00ADm"));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00ADm"));
   }
}
// The example displays the following output:
//       6
//       5
//       1
//       1
//       4
//       3

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim softHyphen As String = ChrW(&h00AD)
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      ' Find the index of the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen))
      
      ' Find the index of the last soft hyphen followed by "n".
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen + "n"))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen + "n"))
      
      ' Find the index of the last soft hyphen followed by "m".
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen + "m"))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen + "m"))
   End Sub
End Module
' The example displays the following output:
'       6
'       5
'       1
'       1
'       4
'       3

Se även

IndexOf(String, Char)

Gäller för

LastIndexOf(String, Char)

Söker efter det angivna tecknet och returnerar det nollbaserade indexet för den senaste förekomsten i hela källsträngen.

public:
 virtual int LastIndexOf(System::String ^ source, char value);

public virtual int LastIndexOf(string source, char value);

abstract member LastIndexOf : string * char -> int
override this.LastIndexOf : string * char -> int

Public Overridable Function LastIndexOf (source As String, value As Char) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: Char

Tecknet som ska hittas i source.

Returer

Int32

Det nollbaserade indexet för den senaste förekomsten av value, om det hittas, inom source; annars -1.

Undantag

ArgumentNullException

source är null.

Exempel

I följande exempel fastställs indexen för de första och sista förekomsterna av ett tecken eller en delsträng i en sträng.

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE" ), myComp.LastIndexOf( myStr, "AE" ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae" ), myComp.LastIndexOf( myStr, "ae" ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ' ), myComp.LastIndexOf( myStr, 'Æ' ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ' ), myComp.LastIndexOf( myStr, 'æ' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308" ), myComp.LastIndexOf( myStr, "U\u0308" ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308" ), myComp.LastIndexOf( myStr, "u\u0308" ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü' ), myComp.LastIndexOf( myStr, 'Ü' ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü' ), myComp.LastIndexOf( myStr, 'ü' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE"), myComp.LastIndexOf(myStr, "AE"))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae"), myComp.LastIndexOf(myStr, "ae"))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c), myComp.LastIndexOf(myStr, "Æ"c))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c), myComp.LastIndexOf(myStr, "æ"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308)))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308)))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c), myComp.LastIndexOf(myStr, "Ü"c))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c), myComp.LastIndexOf(myStr, "ü"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 
         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'No options    : Is AE or ae the same as Æ or æ?
'           AE :    f                    l
'           ae :          f                   l
'            Æ :    f                    l
'            æ :          f                   l
'Ordinal       : Is AE or ae the same as Æ or æ?
'           AE :    b
'           ae :          b
'            Æ :                         b
'            æ :                              b
'IgnoreCase    : Is AE or ae the same as Æ or æ?
'           AE :    f                         l
'           ae :    f                         l
'            Æ :    f                         l
'            æ :    f                         l
'
'No options    : Is U" or u" the same as Ü or ü?
'           U" :    f                    l
'           u" :          f                   l
'            Ü :    f                    l
'            ü :          f                   l
'Ordinal       : Is U" or u" the same as Ü or ü?
'           U" :    b
'           u" :          b
'            Ü :                         b
'            ü :                              b
'IgnoreCase    : Is U" or u" the same as Ü or ü?
'           U" :    f                         l
'           u" :    f                         l
'            Ü :    f                         l
'            ü :    f                         l

Kommentarer

Källsträngen söks bakåt med början i slutet av strängen och slutar i början av strängen.

Note

Anteckningar till anropare

Teckenuppsättningar innehåller okunniga tecken, som är tecken som inte beaktas när du utför en språklig eller kulturkänslig sortering. I en kulturkänslig sökning, om value är ett okunnigt tecken, motsvarar resultatet att söka med det tecknet borttaget. I det här fallet LastIndexOf(String, Char) returnerar metoden alltid den sista indexpositionen i source för att indikera att matchningen hittas i slutet av source. I följande exempel LastIndexOf(String, Char) används metoden för att hitta det mjuka bindestrecket (U+00AD) i två strängar. Endast en av strängarna innehåller ett mjukt bindestreck. I båda fallen, eftersom det mjuka bindestrecket är ett okunnigt tecken, returnerar metoden den sista indexpositionen i strängen för att indikera att den har hittat en matchning i slutet av strängen.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      // Find the index of the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, '\u00AD'));
      Console.WriteLine(ci.LastIndexOf(s2, '\u00AD'));
   }
}
// The example displays the following output:
//       6
//       5

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim softHyphen As Char = ChrW(&h00AD)
      
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      ' Find the index of the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, softHyphen))
      Console.WriteLine(ci.LastIndexOf(s2, softHyphen))
   End Sub
End Module
' The example displays the following output:
'       6
'       5

Se även

IndexOf(String, Char)

Gäller för

LastIndexOf(String, String, Int32)

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex);

public virtual int LastIndexOf(string source, string value, int startIndex);

abstract member LastIndexOf : string * string * int -> int
override this.LastIndexOf : string * string * int -> int

Public Overridable Function LastIndexOf (source As String, value As String, startIndex As Integer) As Integer

Parametrar

source: String

Strängen som ska sökas.

value: String

Strängen som ska hittas i source.

startIndex: Int32

Det nollbaserade startindexet för bakåtsökningen.

Returer

Int32

Undantag

ArgumentNullException

source är null.

-eller-

value är null.

ArgumentOutOfRangeException

startIndex ligger utanför intervallet för giltiga index för source.

Exempel

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 20;
      // myT1 is the string used for padding.
      String myT1;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 20
      ' myT1 is the string used for padding.
      Dim myT1 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS]), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS]), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS]), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS]))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS]))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS]))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.Ordinal))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.Ordinal))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS]), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS]))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS]))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS]))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))
      
      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'IndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                              f
'            Æ :                         f
'            æ :                              f
'Ordinal       : -------------------- as Æ or æ?
'           AE :
'           ae :
'            Æ :                         f
'            æ :                              f
'IgnoreCase    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                         f
'            Æ :                         f
'            æ :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :    l
'            æ :          l
'Ordinal       : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :
'            æ :
'IgnoreCase    : Is AE or ae the same ----------
'           AE :          l
'           ae :          l
'            Æ :          l
'            æ :          l
'
'IndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                              f
'            Ü :                         f
'            ü :                              f
'Ordinal       : -------------------- as Ü or ü?
'           U" :
'           u" :
'            Ü :                         f
'            ü :                              f
'IgnoreCase    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                         f
'            Ü :                         f
'            ü :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :    l
'            ü :          l
'Ordinal       : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :
'            ü :
'IgnoreCase    : Is U" or u" the same ----------
'           U" :          l
'           u" :          l
'            Ü :          l
'            ü :          l

Kommentarer

Källsträngen söks bakåt med början och startIndex slutar i början av strängen.

Note

Anteckningar till anropare

Teckenuppsättningar innehåller okunniga tecken, som är tecken som inte beaktas när du utför en språklig eller kulturkänslig sortering. I en kulturkänslig sökning, om value innehåller ett okunnigt tecken, motsvarar resultatet att söka med det tecknet borttaget. Om value endast består av ett eller flera okunniga tecken LastIndexOf(String, String, Int32) returnerar startIndexmetoden alltid , vilket är teckenpositionen där sökningen börjar. I följande exempel LastIndexOf(String, String, Int32) används metoden för att hitta en delsträng som innehåller ett mjukt bindestreck (U+00AD) och som föregår eller innehåller det sista "m" i en sträng. Eftersom det mjuka bindestrecket i söksträngen ignoreras returnerar anropet metoden för att hitta en delsträng som består av det mjuka bindestrecket och "m" returnerar positionen för "m" i strängen, medan anropet för att hitta en delsträng som består av det mjuka bindestrecket och "n" returnerar positionen för "n". När söksträngen endast innehåller det mjuka bindestrecket returnerar metoden indexet för "m", som representerar värdet för startIndex.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      int position = 0;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      // Find the index of the soft hyphen.
      position = ci.LastIndexOf(s1, "m");
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, "\u00AD", position));

      position = ci.LastIndexOf(s2, "m");
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, "\u00AD", position));

      // Find the index of the soft hyphen followed by "n".
      position = ci.LastIndexOf(s1, "m");
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, "\u00ADn", position));

      position = ci.LastIndexOf(s2, "m");
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, "\u00ADn", position));

      // Find the index of the soft hyphen followed by "m".
      position = ci.LastIndexOf(s1, "m");
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, "\u00ADm", position));

      position = ci.LastIndexOf(s2, "m");
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, "\u00ADm", position));
   }
}
// The example displays the following output:
//       'm' at position 4
//       4
//       'm' at position 3
//       3
//       'm' at position 4
//       1
//       'm' at position 3
//       1
//       'm' at position 4
//       4
//       'm' at position 3
//       3

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo
      
      Dim position As Integer
      Dim softHyphen As String = ChrW(&h00AD)
      
      Dim s1 As String = "ani" + softHyphen + "mal"
      Dim s2 As String = "animal"
      
      ' Find the index of the soft hyphen.
      position = ci.LastIndexOf(s1, "m")
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen, position))
      End If
         
      position = ci.LastIndexOf(s2, "m")
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen, position))
      End If
      
      ' Find the index of the soft hyphen followed by "n".
      position = ci.LastIndexOf(s1, "m")
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen + "n", position))
      End If
         
      position = ci.LastIndexOf(s2, "m")
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen + "n", position))
      End If
      
      ' Find the index of the soft hyphen followed by "m".
      position = ci.LastIndexOf(s1, "m")
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s1, softHyphen + "m", position))
      End If
      
      position = ci.LastIndexOf(s2, "m")
      Console.WriteLine("'m' at position {0}", position)
      If position >= 0 Then
         Console.WriteLine(ci.LastIndexOf(s2, softHyphen + "m", position))
      End If
   End Sub
End Module
' The example displays the following output:
'       'm' at position 4
'       4
'       'm' at position 3
'       3
'       'm' at position 4
'       1
'       'm' at position 3
'       1
'       'm' at position 4
'       4
'       'm' at position 3
'       3

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IndexOf(String, Char)

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