Type.IsPointer Eigenschap
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Hiermee wordt een waarde opgehaald die aangeeft of de Type aanwijzer een aanwijzer is.
public:
virtual property bool IsPointer { bool get(); };
public:
property bool IsPointer { bool get(); };
public virtual bool IsPointer { get; }
public bool IsPointer { get; }
member this.IsPointer : bool
Public Overridable ReadOnly Property IsPointer As Boolean
Public ReadOnly Property IsPointer As Boolean
Waarde van eigenschap
trueals de Type aanwijzer is; anders. false
Implementeringen
Voorbeelden
In het volgende voorbeeld ziet u een gebruik van de IsPointer eigenschap.
using System;
using System.Reflection;
public class MyTypeDelegator : TypeDelegator
{
public string myElementType = null;
private Type myType = null ;
public MyTypeDelegator(Type myType) : base(myType)
{
this.myType = myType;
}
// Override Type.HasElementTypeImpl().
protected override bool HasElementTypeImpl()
{
// Determine whether the type is an array.
if(myType.IsArray)
{
myElementType = "array";
return true;
}
// Determine whether the type is a reference.
if(myType.IsByRef)
{
myElementType = "reference";
return true;
}
// Determine whether the type is a pointer.
if(myType.IsPointer)
{
myElementType = "pointer";
return true;
}
// Return false if the type is not a reference, array, or pointer type.
return false;
}
}
public class Type_HasElementTypeImpl
{
public static void Main()
{
try
{
int myInt = 0 ;
int[] myArray = new int[5];
MyTypeDelegator myType = new MyTypeDelegator(myArray.GetType());
// Determine whether myType is an array, pointer, reference type.
Console.WriteLine("\nDetermine whether a variable is an array, pointer, or reference type.\n");
if( myType.HasElementType)
Console.WriteLine("The type of myArray is {0}.", myType.myElementType);
else
Console.WriteLine("myArray is not an array, pointer, or reference type.");
myType = new MyTypeDelegator(myInt.GetType());
// Determine whether myType is an array, pointer, reference type.
if( myType.HasElementType)
Console.WriteLine("The type of myInt is {0}.", myType.myElementType);
else
Console.WriteLine("myInt is not an array, pointer, or reference type.");
}
catch( Exception e )
{
Console.WriteLine("Exception: {0}", e.Message);
}
}
}
open System.Reflection
type MyTypeDelegator(myType) =
inherit TypeDelegator(myType)
[<DefaultValue>]
val mutable public myElementType: string
// Override Type.HasElementTypeImpl().
override this.HasElementTypeImpl() =
// Determine whether the type is an array.
if myType.IsArray then
this.myElementType <- "array"
true
// Determine whether the type is a reference.
elif myType.IsByRef then
this.myElementType <- "reference"
true
// Determine whether the type is a pointer.
elif myType.IsPointer then
this.myElementType <- "pointer"
true
// Return false if the type is not a reference, array, or pointer type.
else false
try
let myInt = 0
let myArray = Array.zeroCreate<int> 5
let myType = MyTypeDelegator(myArray.GetType())
// Determine whether myType is an array, pointer, reference type.
printfn "\nDetermine whether a variable is an array, pointer, or reference type.\n"
if myType.HasElementType then
printfn $"The type of myArray is {myType.myElementType}."
else
printfn "myArray is not an array, pointer, or reference type."
let myType = MyTypeDelegator(myInt.GetType())
// Determine whether myType is an array, pointer, reference type.
if myType.HasElementType then
printfn $"The type of myInt is {myType.myElementType}."
else
printfn "myInt is not an array, pointer, or reference type."
with e ->
printfn $"Exception: {e.Message}"
Imports System.Reflection
Public Class MyTypeDelegator
Inherits TypeDelegator
Public myElementType As String = Nothing
Private myType As Type = Nothing
Public Sub New(ByVal myType As Type)
MyBase.New(myType)
Me.myType = myType
End Sub
' Override Type.HasElementTypeImpl().
Protected Overrides Function HasElementTypeImpl() As Boolean
' Determine whether the type is an array.
If myType.IsArray Then
myElementType = "array"
Return True
End If
' Determine whether the type is a reference.
If myType.IsByRef Then
myElementType = "reference"
Return True
End If
' Determine whether the type is a pointer.
If myType.IsPointer Then
myElementType = "pointer"
Return True
End If
' The type is not a reference, array, or pointer type.
Return False
End Function 'HasElementTypeImpl
End Class
Public Class Type_HasElementTypeImpl
Public Shared Sub Main()
Try
Dim myInt As Integer = 0
Dim myArray(4) As Integer
Dim myType As New MyTypeDelegator(myArray.GetType())
Console.WriteLine(ControlChars.NewLine + "Determine whether a variable refers to an array or pointer or reference type." + ControlChars.NewLine)
' Determine whether myType is an array, pointer, reference type.
If myType.HasElementType Then
Console.WriteLine("The type of myArray is {0}.", myType.myElementType.ToString())
Else
Console.WriteLine("myArray is not an array, pointer, or reference type.")
End If
myType = New MyTypeDelegator(myInt.GetType())
' Determine whether myType is an array, pointer, reference type.
If myType.HasElementType Then
Console.WriteLine("The type of myInt is {0}.", myType.myElementType.ToString())
Else
Console.WriteLine("myInt is not an array, pointer, or reference type.")
End If
Catch e As Exception
Console.WriteLine("Exception: {0}", e.Message.ToString())
End Try
End Sub
End Class
Opmerkingen
Als de huidige Type een algemeen type of een typeparameter in de definitie van een algemeen type of algemene methode vertegenwoordigt, retourneert falsedeze eigenschap altijd .
Deze eigenschap is alleen-lezen.