Type.IsContextfulImpl Type.IsContextfulImpl Type.IsContextfulImpl Type.IsContextfulImpl Method

定义

实现 IsContextful 属性并确定 Type 在上下文中是否可以被承载。Implements the IsContextful property and determines whether the Type can be hosted in a context.

protected:
 virtual bool IsContextfulImpl();
protected virtual bool IsContextfulImpl ();
abstract member IsContextfulImpl : unit -> bool
override this.IsContextfulImpl : unit -> bool
Protected Overridable Function IsContextfulImpl () As Boolean

返回

如果 Type 能够在某个上下文中承载,则为 true;否则为 falsetrue if the Type can be hosted in a context; otherwise, false.

示例

下面的示例演示IsContextfulImpl方法的用法。The following example demonstrates a use of the IsContextfulImpl method.

using namespace System;
using namespace System::Reflection;

public ref class MyTypeDelegatorClass: public TypeDelegator
{
public:
   String^ myElementType;

private:
   Type^ myType;

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

protected:

   // Override IsContextfulImpl.
   virtual bool IsContextfulImpl() override
   {
      
      // Check whether the type is contextful.
      if ( myType->IsContextful )
      {
         myElementType = " is contextful ";
         return true;
      }

      return false;
   }

};

public ref class MyTypeDemoClass{};


// This class demonstrates IsContextfulImpl.
public ref class MyContextBoundClass: public ContextBoundObject
{
public:
   String^ myString;
};

int main()
{
   try
   {
      MyTypeDelegatorClass^ myType;
      Console::WriteLine( "Check whether MyContextBoundClass can be hosted in a context." );
      
      // Check whether MyContextBoundClass is contextful.
      myType = gcnew MyTypeDelegatorClass( MyContextBoundClass::typeid );
      if ( myType->IsContextful )
      {
         Console::WriteLine( "{0} can be hosted in a context.", MyContextBoundClass::typeid );
      }
      else
      {
         Console::WriteLine( "{0} cannot be hosted in a context.", MyContextBoundClass::typeid );
      }
      myType = gcnew MyTypeDelegatorClass( MyTypeDemoClass::typeid );
      Console::WriteLine( "\nCheck whether MyTypeDemoClass can be hosted in a context." );
      if ( myType->IsContextful )
      {
         Console::WriteLine( "{0} can be hosted in a context.", MyTypeDemoClass::typeid );
      }
      else
      {
         Console::WriteLine( "{0} cannot be hosted in a context.", MyTypeDemoClass::typeid );
      }
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception: {0}", e->Message );
   }
}
using System;
using System.Reflection;
public class MyTypeDelegatorClass : TypeDelegator
{
    public string myElementType = null;
    private Type myType = null ; 

    public MyTypeDelegatorClass(Type myType) : base(myType)
    {
        this.myType = myType;
    }
    // Override IsContextfulImpl.
    protected override bool IsContextfulImpl()
    {
        // Check whether the type is contextful.
        if(myType.IsContextful)
        { 
            myElementType = " is contextful ";
            return true;
        }
        return false;
    }
}
public class MyTypeDemoClass
{
    public static void Main()
    {
        try
        {
            MyTypeDelegatorClass myType;
            Console.WriteLine ("Check whether MyContextBoundClass can be hosted in a context.");
            // Check whether MyContextBoundClass is contextful.
            myType = new MyTypeDelegatorClass(typeof(MyContextBoundClass));
            if( myType.IsContextful)
            {
                Console.WriteLine(typeof(MyContextBoundClass) + " can be hosted in a context.");
            }
            else
            {
                Console.WriteLine(typeof(MyContextBoundClass) + " cannot be hosted in a context.");
            }
            // Check whether the int type is contextful.
            myType = new MyTypeDelegatorClass(typeof(MyTypeDemoClass));
            Console.WriteLine ("\nCheck whether MyTypeDemoClass can be hosted in a context.");
            if( myType.IsContextful)
            {
                Console.WriteLine(typeof(MyTypeDemoClass) + " can be hosted in a context.");
            }
            else
            {
                Console.WriteLine(typeof(MyTypeDemoClass) + " cannot be hosted in a context.");
            }
        }
        catch( Exception e )
        {
            Console.WriteLine("Exception: {0}", e.Message);
        }
    }
}
// This class demonstrates IsContextfulImpl.
public class MyContextBoundClass : ContextBoundObject
{
    public string myString = "This class is used to demonstrate members of the Type class.";
}
Imports System.Reflection

Public Class MyTypeDelegatorClass
    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 'New
    ' Override IsContextfulImpl.
    Protected Overrides Function IsContextfulImpl() As Boolean
        ' Check whether the type is contextful.
        If myType.IsContextful Then
            myElementType = " is contextful "
            Return True
        End If
        Return False
    End Function 'IsContextfulImpl
End Class 'MyTypeDelegatorClass
Public Class MyTypeDemoClass
    Public Shared Sub Main()
        Try
            Dim myType As MyTypeDelegatorClass
            Console.WriteLine("Check whether MyContextBoundClass can be hosted in a context.")
            ' Check whether MyContextBoundClass is contextful.
            myType = New MyTypeDelegatorClass(GetType(MyContextBoundClass))
            If myType.IsContextful Then
                Console.WriteLine(GetType(MyContextBoundClass).ToString() + " can be hosted in a context.")
            Else
                Console.WriteLine(GetType(MyContextBoundClass).ToString() + " cannot be hosted in a context.")
            End If
            ' Check whether the int type is contextful.
            myType = New MyTypeDelegatorClass(GetType(MyTypeDemoClass))
            Console.WriteLine(ControlChars.NewLine + "Check whether MyTypeDemoClass can be hosted in a context.")
            If myType.IsContextful Then
                Console.WriteLine(GetType(MyTypeDemoClass).ToString() + " can be hosted in a context.")
            Else
                Console.WriteLine(GetType(MyTypeDemoClass).ToString() + " cannot be hosted in a context.")
            End If
        Catch e As Exception
            Console.WriteLine("Exception: {0}", e.Message.ToString())
        End Try
    End Sub 'Main
End Class 'MyTypeDemoClass
' This class demonstrates the IsContextfulImpl method.
Public Class MyContextBoundClass
    Inherits ContextBoundObject
    Public myString As String = "This class is used to demonstrate members of the Type class."
End Class 'MyContextBoundClass

注解

此方法可由派生类重写。This method can be overridden by a derived class.

上下文会截获对类成员的调用,并强制实施应用于类的策略,如同步。A context intercepts calls to the class members and enforce policies that are applied to the class, such as synchronization.

适用于

另请参阅