Type.HasElementTypeImpl Methode

Referenz

Definition

Namespace:: System

Assemblys:: netstandard.dll, System.Runtime.dll

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Quelle:: Type.cs

Quelle:: Type.cs

Quelle:: Type.cs

Wichtig

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Implementiert beim Überschreiben in einer abgeleiteten Klasse die HasElementType-Eigenschaft und bestimmt, ob der aktuelle Type einen anderen Typ umfasst oder auf einen solchen verweist, d. h. ob der aktuelle Type ein Array oder Zeiger ist oder als Verweis übergeben wird.

protected:
 abstract bool HasElementTypeImpl();

protected abstract bool HasElementTypeImpl();

abstract member HasElementTypeImpl : unit -> bool

Protected MustOverride Function HasElementTypeImpl () As Boolean

Gibt zurück

Boolean

true, wenn Type ein Array oder ein Zeiger ist oder als Verweis übergeben wird, andernfalls false.

Beispiele

Im folgenden Beispiel wird die -Klasse MyTypeDelegatordefiniert, die die HasElementTypeImpl -Methode außer Kraft setzt. Die Standard-Klasse überprüft die HasElementType Eigenschaft und zeigt den Elementtyp an.

using namespace System;
using namespace System::Reflection;
public ref class MyTypeDelegator: public TypeDelegator
{
public:
   String^ myElementType;

private:
   Type^ myType;

public:
   MyTypeDelegator( Type^ myType )
      : TypeDelegator( myType )
   {
      this->myType = myType;
   }


protected:

   // Override Type::HasElementTypeImpl().
   virtual bool HasElementTypeImpl() override
   {
      
      // 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;
   }

};

int main()
{
   try
   {
      int myInt = 0;
      array<Int32>^myArray = gcnew array<Int32>(5);
      MyTypeDelegator^ myType = gcnew 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 = gcnew 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 );
   }

}

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

Hinweise

Beispielsweise Type.GetType("Int32[]"). HasElementTypeImpl gibt true, wohingegen Type.GetType("Int32"). HasElementTypeImpl gibt false. HasElementTypeImpl gibt auch für "Int32*" und "Int32&" zurück true .

Gilt für:

Produkt	Versionen
.NET	Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

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