Type.IsContextfulImpl Method

Definition

Namespace:

System

Assembly:

System.Runtime.dll

Source:

Type.cs

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

Returns

Boolean

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

Examples

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.";
}

open System
open System.Reflection

type MyTypeDelegatorClass(myType) =
    inherit TypeDelegator(myType) 
    member val myElementType = null with get, set
    
    // Override IsContextfulImpl.
    override this.IsContextfulImpl() = 
        // Check whether the type is contextful.
        if myType.IsContextful then
            this.myElementType <- " is contextful "
            true
        else false

// This class demonstrates IsContextfulImpl.
type MyContextBoundClass() =
    inherit ContextBoundObject()
    let myString = "This class is used to demonstrate members of the Type class."

type MyTypeDemoClass() = class end

try
    printfn "Check whether MyContextBoundClass can be hosted in a context."
    // Check whether MyContextBoundClass is contextful.
    let myType = MyTypeDelegatorClass typeof<MyContextBoundClass>
    if myType.IsContextful then
        printfn $"{typeof<MyContextBoundClass>} can be hosted in a context."
    else
        printfn $"{typeof<MyContextBoundClass>} cannot be hosted in a context."
    // Check whether the int type is contextful.
    let myType = MyTypeDelegatorClass typeof<MyTypeDemoClass>
    printfn "\nCheck whether MyTypeDemoClass can be hosted in a context."
    if myType.IsContextful then
        printfn $"{typeof<MyTypeDemoClass>} can be hosted in a context."
    else
        printfn $"{typeof<MyTypeDemoClass>} cannot be hosted in a context."
with e ->
    printfn $"Exception: {e.Message}"

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
    ' 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
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
End Class
' 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

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.

See also

• IsContextful