HybridDictionary Classe

Definizione

public ref class HybridDictionary : System::Collections::IDictionary

public class HybridDictionary : System.Collections.IDictionary

[System.Serializable]
public class HybridDictionary : System.Collections.IDictionary

type HybridDictionary = class
    interface ICollection
    interface IEnumerable
    interface IDictionary

[<System.Serializable>]
type HybridDictionary = class
    interface IDictionary
    interface ICollection
    interface IEnumerable

Public Class HybridDictionary
Implements IDictionary

Ereditarietà

Object

HybridDictionary

Derivato

System.Web.Mobile.CookielessData

Attributi

SerializableAttribute

Implementazioni

ICollection IDictionary IEnumerable

Esempio

Nell'esempio di codice seguente vengono illustrati diversi metodi e proprietà di HybridDictionary.

using System;
using System.Collections;
using System.Collections.Specialized;

public class SamplesHybridDictionary  {

   public static void Main()  {

      // Creates and initializes a new HybridDictionary.
      HybridDictionary myCol = new HybridDictionary();
      myCol.Add( "Braeburn Apples", "1.49" );
      myCol.Add( "Fuji Apples", "1.29" );
      myCol.Add( "Gala Apples", "1.49" );
      myCol.Add( "Golden Delicious Apples", "1.29" );
      myCol.Add( "Granny Smith Apples", "0.89" );
      myCol.Add( "Red Delicious Apples", "0.99" );
      myCol.Add( "Plantain Bananas", "1.49" );
      myCol.Add( "Yellow Bananas", "0.79" );
      myCol.Add( "Strawberries", "3.33" );
      myCol.Add( "Cranberries", "5.98" );
      myCol.Add( "Navel Oranges", "1.29" );
      myCol.Add( "Grapes", "1.99" );
      myCol.Add( "Honeydew Melon", "0.59" );
      myCol.Add( "Seedless Watermelon", "0.49" );
      myCol.Add( "Pineapple", "1.49" );
      myCol.Add( "Nectarine", "1.99" );
      myCol.Add( "Plums", "1.69" );
      myCol.Add( "Peaches", "1.99" );

      // Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine( "Displays the elements using foreach:" );
      PrintKeysAndValues1( myCol );

      // Display the contents of the collection using the enumerator.
      Console.WriteLine( "Displays the elements using the IDictionaryEnumerator:" );
      PrintKeysAndValues2( myCol );

      // Display the contents of the collection using the Keys, Values, Count, and Item properties.
      Console.WriteLine( "Displays the elements using the Keys, Values, Count, and Item properties:" );
      PrintKeysAndValues3( myCol );

      // Copies the HybridDictionary to an array with DictionaryEntry elements.
      DictionaryEntry[] myArr = new DictionaryEntry[myCol.Count];
      myCol.CopyTo( myArr, 0 );

      // Displays the values in the array.
      Console.WriteLine( "Displays the elements in the array:" );
      Console.WriteLine( "   KEY                       VALUE" );
      for ( int i = 0; i < myArr.Length; i++ )
         Console.WriteLine( "   {0,-25} {1}", myArr[i].Key, myArr[i].Value );
      Console.WriteLine();

      // Searches for a key.
      if ( myCol.Contains( "Kiwis" ) )
         Console.WriteLine( "The collection contains the key \"Kiwis\"." );
      else
         Console.WriteLine( "The collection does not contain the key \"Kiwis\"." );
      Console.WriteLine();

      // Deletes a key.
      myCol.Remove( "Plums" );
      Console.WriteLine( "The collection contains the following elements after removing \"Plums\":" );
      PrintKeysAndValues1( myCol );

      // Clears the entire collection.
      myCol.Clear();
      Console.WriteLine( "The collection contains the following elements after it is cleared:" );
      PrintKeysAndValues1( myCol );
   }

   // Uses the foreach statement which hides the complexity of the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues1( IDictionary myCol )  {
      Console.WriteLine( "   KEY                       VALUE" );
      foreach ( DictionaryEntry de in myCol )
         Console.WriteLine( "   {0,-25} {1}", de.Key, de.Value );
      Console.WriteLine();
   }

   // Uses the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues2( IDictionary myCol )  {
      IDictionaryEnumerator myEnumerator = myCol.GetEnumerator();
      Console.WriteLine( "   KEY                       VALUE" );
      while ( myEnumerator.MoveNext() )
         Console.WriteLine( "   {0,-25} {1}", myEnumerator.Key, myEnumerator.Value );
      Console.WriteLine();
   }

   // Uses the Keys, Values, Count, and Item properties.
   public static void PrintKeysAndValues3( HybridDictionary myCol )  {
      String[] myKeys = new String[myCol.Count];
      myCol.Keys.CopyTo( myKeys, 0 );

      Console.WriteLine( "   INDEX KEY                       VALUE" );
      for ( int i = 0; i < myCol.Count; i++ )
         Console.WriteLine( "   {0,-5} {1,-25} {2}", i, myKeys[i], myCol[myKeys[i]] );
      Console.WriteLine();
   }
}

/*
This code produces output similar to the following:

Displays the elements using foreach:
   KEY                       VALUE
   Strawberries              3.33
   Yellow Bananas            0.79
   Cranberries               5.98
   Grapes                    1.99
   Granny Smith Apples       0.89
   Seedless Watermelon       0.49
   Honeydew Melon            0.59
   Red Delicious Apples      0.99
   Navel Oranges             1.29
   Fuji Apples               1.29
   Plantain Bananas          1.49
   Gala Apples               1.49
   Pineapple                 1.49
   Plums                     1.69
   Braeburn Apples           1.49
   Peaches                   1.99
   Golden Delicious Apples   1.29
   Nectarine                 1.99

Displays the elements using the IDictionaryEnumerator:
   KEY                       VALUE
   Strawberries              3.33
   Yellow Bananas            0.79
   Cranberries               5.98
   Grapes                    1.99
   Granny Smith Apples       0.89
   Seedless Watermelon       0.49
   Honeydew Melon            0.59
   Red Delicious Apples      0.99
   Navel Oranges             1.29
   Fuji Apples               1.29
   Plantain Bananas          1.49
   Gala Apples               1.49
   Pineapple                 1.49
   Plums                     1.69
   Braeburn Apples           1.49
   Peaches                   1.99
   Golden Delicious Apples   1.29
   Nectarine                 1.99

Displays the elements using the Keys, Values, Count, and Item properties:
   INDEX KEY                       VALUE
   0     Strawberries              3.33
   1     Yellow Bananas            0.79
   2     Cranberries               5.98
   3     Grapes                    1.99
   4     Granny Smith Apples       0.89
   5     Seedless Watermelon       0.49
   6     Honeydew Melon            0.59
   7     Red Delicious Apples      0.99
   8     Navel Oranges             1.29
   9     Fuji Apples               1.29
   10    Plantain Bananas          1.49
   11    Gala Apples               1.49
   12    Pineapple                 1.49
   13    Plums                     1.69
   14    Braeburn Apples           1.49
   15    Peaches                   1.99
   16    Golden Delicious Apples   1.29
   17    Nectarine                 1.99

Displays the elements in the array:
   KEY                       VALUE
   Strawberries              3.33
   Yellow Bananas            0.79
   Cranberries               5.98
   Grapes                    1.99
   Granny Smith Apples       0.89
   Seedless Watermelon       0.49
   Honeydew Melon            0.59
   Red Delicious Apples      0.99
   Navel Oranges             1.29
   Fuji Apples               1.29
   Plantain Bananas          1.49
   Gala Apples               1.49
   Pineapple                 1.49
   Plums                     1.69
   Braeburn Apples           1.49
   Peaches                   1.99
   Golden Delicious Apples   1.29
   Nectarine                 1.99

The collection does not contain the key "Kiwis".

The collection contains the following elements after removing "Plums":
   KEY                       VALUE
   Strawberries              3.33
   Yellow Bananas            0.79
   Cranberries               5.98
   Grapes                    1.99
   Granny Smith Apples       0.89
   Seedless Watermelon       0.49
   Honeydew Melon            0.59
   Red Delicious Apples      0.99
   Navel Oranges             1.29
   Fuji Apples               1.29
   Plantain Bananas          1.49
   Gala Apples               1.49
   Pineapple                 1.49
   Braeburn Apples           1.49
   Peaches                   1.99
   Golden Delicious Apples   1.29
   Nectarine                 1.99

The collection contains the following elements after it is cleared:
   KEY                       VALUE

*/

Imports System.Collections
Imports System.Collections.Specialized

Public Class SamplesHybridDictionary   

   Public Shared Sub Main()

      ' Creates and initializes a new HybridDictionary.
      Dim myCol As New HybridDictionary()
      myCol.Add("Braeburn Apples", "1.49")
      myCol.Add("Fuji Apples", "1.29")
      myCol.Add("Gala Apples", "1.49")
      myCol.Add("Golden Delicious Apples", "1.29")
      myCol.Add("Granny Smith Apples", "0.89")
      myCol.Add("Red Delicious Apples", "0.99")
      myCol.Add("Plantain Bananas", "1.49")
      myCol.Add("Yellow Bananas", "0.79")
      myCol.Add("Strawberries", "3.33")
      myCol.Add("Cranberries", "5.98")
      myCol.Add("Navel Oranges", "1.29")
      myCol.Add("Grapes", "1.99")
      myCol.Add("Honeydew Melon", "0.59")
      myCol.Add("Seedless Watermelon", "0.49")
      myCol.Add("Pineapple", "1.49")
      myCol.Add("Nectarine", "1.99")
      myCol.Add("Plums", "1.69")
      myCol.Add("Peaches", "1.99")

      ' Display the contents of the collection using For Each. This is the preferred method.
      Console.WriteLine("Displays the elements using For Each:")
      PrintKeysAndValues1(myCol)

      ' Display the contents of the collection using the enumerator.
      Console.WriteLine("Displays the elements using the IDictionaryEnumerator:")
      PrintKeysAndValues2(myCol)

      ' Display the contents of the collection using the Keys, Values, Count, and Item properties.
      Console.WriteLine("Displays the elements using the Keys, Values, Count, and Item properties:")
      PrintKeysAndValues3(myCol)

      ' Copies the HybridDictionary to an array with DictionaryEntry elements.
      Dim myArr(myCol.Count) As DictionaryEntry
      myCol.CopyTo(myArr, 0)

      ' Displays the values in the array.
      Console.WriteLine("Displays the elements in the array:")
      Console.WriteLine("   KEY                       VALUE")
      Dim i As Integer
      For i = 0 To myArr.Length - 1
         Console.WriteLine("   {0,-25} {1}", myArr(i).Key, myArr(i).Value)
      Next i
      Console.WriteLine()

      ' Searches for a key.
      If myCol.Contains("Kiwis") Then
         Console.WriteLine("The collection contains the key ""Kiwis"".")
      Else
         Console.WriteLine("The collection does not contain the key ""Kiwis"".")
      End If
      Console.WriteLine()

      ' Deletes a key.
      myCol.Remove("Plums")
      Console.WriteLine("The collection contains the following elements after removing ""Plums"":")
      PrintKeysAndValues1(myCol)

      ' Clears the entire collection.
      myCol.Clear()
      Console.WriteLine("The collection contains the following elements after it is cleared:")
      PrintKeysAndValues1(myCol)

   End Sub

   ' Uses the For Each statement which hides the complexity of the enumerator.
   ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintKeysAndValues1(myCol As IDictionary)

      Console.WriteLine("   KEY                       VALUE")
      Dim de As DictionaryEntry
      For Each de In  myCol
         Console.WriteLine("   {0,-25} {1}", de.Key, de.Value)
      Next de
      Console.WriteLine()

   End Sub


   ' Uses the enumerator. 
   ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintKeysAndValues2(myCol As IDictionary)
      Dim myEnumerator As IDictionaryEnumerator = myCol.GetEnumerator()

      Console.WriteLine("   KEY                       VALUE")
      While myEnumerator.MoveNext()
         Console.WriteLine("   {0,-25} {1}", myEnumerator.Key, myEnumerator.Value)
      End While
      Console.WriteLine()

   End Sub


   ' Uses the Keys, Values, Count, and Item properties.
   Public Shared Sub PrintKeysAndValues3(myCol As HybridDictionary)
      Dim myKeys(myCol.Count) As [String]
      myCol.Keys.CopyTo(myKeys, 0)

      Console.WriteLine("   INDEX KEY                       VALUE")
      Dim i As Integer
      For i = 0 To myCol.Count - 1
         Console.WriteLine("   {0,-5} {1,-25} {2}", i, myKeys(i), myCol(myKeys(i)))
      Next i
      Console.WriteLine()

   End Sub

End Class


'This code produces output similar to the following:
'
'Displays the elements using For Each:
'   KEY                       VALUE
'   Strawberries              3.33
'   Yellow Bananas            0.79
'   Cranberries               5.98
'   Grapes                    1.99
'   Granny Smith Apples       0.89
'   Seedless Watermelon       0.49
'   Honeydew Melon            0.59
'   Red Delicious Apples      0.99
'   Navel Oranges             1.29
'   Fuji Apples               1.29
'   Plantain Bananas          1.49
'   Gala Apples               1.49
'   Pineapple                 1.49
'   Plums                     1.69
'   Braeburn Apples           1.49
'   Peaches                   1.99
'   Golden Delicious Apples   1.29
'   Nectarine                 1.99
'
'Displays the elements using the IDictionaryEnumerator:
'   KEY                       VALUE
'   Strawberries              3.33
'   Yellow Bananas            0.79
'   Cranberries               5.98
'   Grapes                    1.99
'   Granny Smith Apples       0.89
'   Seedless Watermelon       0.49
'   Honeydew Melon            0.59
'   Red Delicious Apples      0.99
'   Navel Oranges             1.29
'   Fuji Apples               1.29
'   Plantain Bananas          1.49
'   Gala Apples               1.49
'   Pineapple                 1.49
'   Plums                     1.69
'   Braeburn Apples           1.49
'   Peaches                   1.99
'   Golden Delicious Apples   1.29
'   Nectarine                 1.99
'
'Displays the elements using the Keys, Values, Count, and Item properties:
'   INDEX KEY                       VALUE
'   0     Strawberries              3.33
'   1     Yellow Bananas            0.79
'   2     Cranberries               5.98
'   3     Grapes                    1.99
'   4     Granny Smith Apples       0.89
'   5     Seedless Watermelon       0.49
'   6     Honeydew Melon            0.59
'   7     Red Delicious Apples      0.99
'   8     Navel Oranges             1.29
'   9     Fuji Apples               1.29
'   10    Plantain Bananas          1.49
'   11    Gala Apples               1.49
'   12    Pineapple                 1.49
'   13    Plums                     1.69
'   14    Braeburn Apples           1.49
'   15    Peaches                   1.99
'   16    Golden Delicious Apples   1.29
'   17    Nectarine                 1.99
'
'Displays the elements in the array:
'   KEY                       VALUE
'   Strawberries              3.33
'   Yellow Bananas            0.79
'   Cranberries               5.98
'   Grapes                    1.99
'   Granny Smith Apples       0.89
'   Seedless Watermelon       0.49
'   Honeydew Melon            0.59
'   Red Delicious Apples      0.99
'   Navel Oranges             1.29
'   Fuji Apples               1.29
'   Plantain Bananas          1.49
'   Gala Apples               1.49
'   Pineapple                 1.49
'   Plums                     1.69
'   Braeburn Apples           1.49
'   Peaches                   1.99
'   Golden Delicious Apples   1.29
'   Nectarine                 1.99
'
'The collection does not contain the key "Kiwis".
'
'The collection contains the following elements after removing "Plums":
'   KEY                       VALUE
'   Strawberries              3.33
'   Yellow Bananas            0.79
'   Cranberries               5.98
'   Grapes                    1.99
'   Granny Smith Apples       0.89
'   Seedless Watermelon       0.49
'   Honeydew Melon            0.59
'   Red Delicious Apples      0.99
'   Navel Oranges             1.29
'   Fuji Apples               1.29
'   Plantain Bananas          1.49
'   Gala Apples               1.49
'   Pineapple                 1.49
'   Braeburn Apples           1.49
'   Peaches                   1.99
'   Golden Delicious Apples   1.29
'   Nectarine                 1.99
'
'The collection contains the following elements after it is cleared:
'   KEY                       VALUE

Commenti

Questa classe è consigliata per i casi in cui il numero di elementi in un dizionario è sconosciuto. Sfrutta le prestazioni migliorate di un ListDictionary oggetto con raccolte di piccole dimensioni e offre la flessibilità di passare a un Hashtable, che gestisce raccolte di dimensioni superiori rispetto ListDictionarya .

Se le dimensioni iniziali dell'insieme sono maggiori delle dimensioni ottimali per un ListDictionaryoggetto , l'insieme viene archiviato in per Hashtable evitare l'overhead della copia di elementi da ListDictionary a .Hashtable

Il costruttore accetta un parametro booleano che consente all'utente di specificare se la raccolta ignora il caso durante il confronto delle stringhe. Se la raccolta fa distinzione tra maiuscole e minuscole, usa le implementazioni della chiave di Object.GetHashCode e Object.Equals. Se la raccolta non fa distinzione tra maiuscole e minuscole, esegue un semplice confronto ordinale senza distinzione tra maiuscole e minuscole, che rispetta solo le regole di maiuscole e minuscole delle impostazioni cultura invarianti. Per impostazione predefinita, la raccolta fa distinzione tra maiuscole e minuscole. Per altre informazioni sulle impostazioni cultura invarianti, vedere System.Globalization.CultureInfo.

Una chiave non può essere Null, ma un valore può.

L'istruzione foreach del linguaggio C# (For Each in Visual Basic) restituisce un oggetto del tipo degli elementi nella raccolta. Poiché ogni elemento di HybridDictionary è una coppia chiave/valore, il tipo di elemento non è il tipo della chiave o il tipo del valore. Il tipo di elemento è DictionaryEntryinvece . Per esempio:

foreach (DictionaryEntry de in myHybridDictionary)
{
    //...
}

For Each de In myHybridDictionary
    '...
Next

L'istruzione foreach è un wrapper intorno all'enumeratore, che consente solo la lettura, non la scrittura nella raccolta.

Thread safety

I membri statici pubblici (Shared in Visual Basic) di questo tipo sono thread-safe. Non è garantito che tutti i membri dell'istanza siano thread-safe.

Questa implementazione non fornisce un wrapper sincronizzato (thread-safe) per un oggetto HybridDictionary, ma le classi derivate possono creare versioni sincronizzate dell'oggetto HybridDictionary usando la SyncRoot proprietà .

L'enumerazione tramite una raccolta non è intrinsecamente una procedura thread-safe. Anche quando una raccolta viene sincronizzata, altri thread possono comunque modificare la raccolta, causando la generazione di un'eccezione da parte dell'enumeratore. Per garantire la thread safety durante l'enumerazione, è possibile bloccare la raccolta durante l'intera enumerazione o intercettare le eccezioni risultanti dalle modifiche apportate da altri thread.

Vedi anche

• IDictionary
• ListDictionary
• Hashtable
• CaseInsensitiveHashCodeProvider
• GetHashCode()
• Equals(Object)
• Esecuzione di operazioni stringa di Culture-Insensitive