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Type.IsContextfulImpl Method

Implements the IsContextful property and determines whether the Type can be hosted in a context.

[Visual Basic]
Protected Overridable Function IsContextfulImpl() As Boolean
[C#]
protected virtual bool IsContextfulImpl();
[C++]
protected: virtual bool IsContextfulImpl();
[JScript]
protected function IsContextfulImpl() : Boolean;

Return Value

true if the Type can be hosted in a context; otherwise, false.

Remarks

This method can be overridden by a derived class.

A context intercepts calls to the class members and enforce policies that are applied to the class, such as synchronization.

Example

[Visual Basic, C#, C++] The following example demonstrates a use of the IsContextfulImpl method.

[Visual Basic] 
Imports System
Imports System.Reflection
Imports Microsoft.VisualBasic
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

[C#] 
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.";
}

[C++] 
#using <mscorlib.dll>

using namespace System;
using namespace System::Reflection;

public __gc class MyTypeDelegatorClass : public TypeDelegator {
public:
   String* myElementType;
private:
   Type* myType;
public:
   MyTypeDelegatorClass(Type* myType) : TypeDelegator(myType) {
      this->myType = myType;
   }
   // Override IsContextfulImpl.
protected:
   bool IsContextfulImpl() {
      // Check whether the type is contextful.
      if (myType->IsContextful) {
         myElementType = S" is contextful ";
         return true;
      }
      return false;
   }
};

public __gc class MyTypeDemoClass {
};

// This class demonstrates IsContextfulImpl.
public __gc class MyContextBoundClass : public ContextBoundObject {
public:
   String* myString;
};

int main() {
   try {
      MyTypeDelegatorClass* myType;
      Console::WriteLine (S"Check whether MyContextBoundClass can be hosted in a context.");
      // Check whether MyContextBoundClass is contextful.
      myType = new MyTypeDelegatorClass(__typeof(MyContextBoundClass));
      if (myType->IsContextful) {
         Console::WriteLine(S"{0} can be hosted in a context.", __typeof(MyContextBoundClass));
      } else {
         Console::WriteLine(S"{0} cannot be hosted in a context.", __typeof(MyContextBoundClass));
      }
      // Check whether the int type is contextful.
      myType = new MyTypeDelegatorClass(__typeof(MyTypeDemoClass));
      Console::WriteLine (S"\nCheck whether MyTypeDemoClass can be hosted in a context.");
      if (myType->IsContextful) {
         Console::WriteLine(S"{0} can be hosted in a context.", __typeof(MyTypeDemoClass));
      } else {
         Console::WriteLine(S"{0} cannot be hosted in a context.", __typeof(MyTypeDemoClass));
      }
   } catch (Exception* e) {
      Console::WriteLine(S"Exception: {0}", e->Message);
   }
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

Type Class | Type Members | System Namespace | IsContextful

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