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ObjectHandle Class

Wraps marshal-by-value object references, allowing them to be returned through an indirection.

Namespace:  System.Runtime.Remoting
Assembly:  mscorlib (in mscorlib.dll)

[ClassInterfaceAttribute(ClassInterfaceType.AutoDual)]
[ComVisibleAttribute(true)]
public class ObjectHandle : MarshalByRefObject, 
	IObjectHandle

The ObjectHandle class is used to pass an object (in a wrapped state) between multiple application domains without loading the metadata for the wrapped object in each AppDomain through which the ObjectHandle travels. Thus, the ObjectHandle class gives the caller control of when the Type of the remote object is loaded into a domain.

The following code example shows how to create an object in another AppDomain, and retrieve a proxy to the object from a ObjectHandle. In this example, you can assume that the code of the MyType class is compiled into an assembly called "ObjectHandleAssembly".

using System;
using System.Runtime.Remoting;


public class MyType : MarshalByRefObject {

   public MyType()  {
      Console.Write("Created an instance of MyType in an AppDomain with the ");
      Console.WriteLine("hash code {0}",AppDomain.CurrentDomain.GetHashCode());
      Console.WriteLine("");
   }

   public int GetAppDomainHashCode() {
      return AppDomain.CurrentDomain.GetHashCode();
   }
}


class Test {

   public static void Main() {

      Console.WriteLine("The hash code of the default AppDomain is {0}.", 
                        AppDomain.CurrentDomain.GetHashCode());
      Console.WriteLine("");

      // Creates another AppDomain.
      AppDomain domain = AppDomain.CreateDomain("AnotherDomain", 
                                                null, 
                                                (AppDomainSetup)null);

      // Creates an instance of MyType defined in the assembly called ObjectHandleAssembly.
      ObjectHandle obj = domain.CreateInstance("ObjectHandleAssembly", "MyType");

      // Unwrapps the proxy to the MyType object created in the other AppDomain.
      MyType testObj = (MyType)obj.Unwrap();

      if(RemotingServices.IsTransparentProxy(testObj))
         Console.WriteLine("The unwrapped object is a proxy.");
      else
         Console.WriteLine("The unwrapped object is not a proxy!");    

      Console.WriteLine("");
      Console.Write("Calling a method on the object located in an AppDomain with the hash code ");
      Console.WriteLine(testObj.GetAppDomainHashCode());
   }
}
#using <mscorlib.dll>

using namespace System;
using namespace System::Runtime::Remoting;


public __gc class MyType : public MarshalByRefObject {

public:
   MyType() {
      Console::Write(S"Created an instance of MyType in an AppDomain with the ");
      Console::WriteLine(S"hash code {0}", __box( AppDomain::CurrentDomain->GetHashCode()));
      Console::WriteLine(S"");
   }

public:
   int GetAppDomainHashCode() {
      return AppDomain::CurrentDomain->GetHashCode();
   }
};



int main() {

   Console::WriteLine(S"The hash code of the default AppDomain is {0}.",
      __box(                        AppDomain::CurrentDomain->GetHashCode()));
   Console::WriteLine(S"");

   // Creates another AppDomain.
   AppDomain*  domain = AppDomain::CreateDomain(S"AnotherDomain",
      0,
      (AppDomainSetup*)0);

   // Creates an instance of MyType defined in the assembly called ObjectHandleAssembly.
   ObjectHandle*  obj = domain->CreateInstance(S"ObjectHandleAssembly", S"MyType");

   // Unwraps the proxy to the MyType object created in the other AppDomain.
   MyType* testObj = dynamic_cast<MyType*>(obj->Unwrap());

   if (RemotingServices::IsTransparentProxy(testObj))
      Console::WriteLine(S"The unwrapped object is a proxy.");
   else
      Console::WriteLine(S"The unwrapped object is not a proxy!");

   Console::WriteLine(S"");
   Console::Write(S"Calling a method on the object located in an AppDomain with the hash code ");
   Console::WriteLine(testObj->GetAppDomainHashCode());
}

System.Object
  System.MarshalByRefObject
    System.Runtime.Remoting.ObjectHandle

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

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