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Type.IsByRef Proprietà

Definizione

Ottiene un valore che indica se l'oggetto Type viene passato per riferimento.

public:
 virtual property bool IsByRef { bool get(); };
public:
 property bool IsByRef { bool get(); };
public virtual bool IsByRef { get; }
public bool IsByRef { get; }
member this.IsByRef : bool
Public Overridable ReadOnly Property IsByRef As Boolean
Public ReadOnly Property IsByRef As Boolean

Valore della proprietà

Boolean

true se Type viene passato per riferimento; in caso contrario, false.

Implementazioni

Esempio

Nell'esempio seguente viene illustrato l'utilizzo IsByRef della proprietà per controllare se un tipo specificato viene passato per riferimento. Nell'esempio viene definita la classe MyTypeDelegator , che esegue l'override del HasElementTypeImpl metodo . La classe principale controlla la HasElementType proprietà e visualizza il tipo di elemento.

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);
        }
    }
}
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

Commenti

Per ottenere il tipo effettivo, dereferenziare il tipo passato per riferimento e quindi chiamare GetElementType su tale tipo.

Si applica a

Vedi anche