ObjectHandle Class
Wraps marshal by value object references, allowing them to be returned through an indirection.
For a list of all members of this type, see ObjectHandle Members.
System.Object
System.MarshalByRefObject
System.Runtime.Remoting.ObjectHandle
[Visual Basic] <ClassInterface(ClassInterfaceType.AutoDual)> Public Class ObjectHandle Inherits MarshalByRefObject Implements IObjectHandle [C#] [ClassInterface(ClassInterfaceType.AutoDual)] public class ObjectHandle : MarshalByRefObject, IObjectHandle [C++] [ClassInterface(ClassInterfaceType::AutoDual)] public __gc class ObjectHandle : public MarshalByRefObject, IObjectHandle [JScript] public ClassInterface(ClassInterfaceType.AutoDual) class ObjectHandle extends MarshalByRefObject implements IObjectHandle
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Remarks
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.
Example
[Visual Basic, C#, C++] The following code example shows how to create an object in another AppDomain, and retrieve a proxy to the object from an ObjectHandle. In this example, you can assume that the code of the MyType class is compiled into an assembly called "ObjectHandleAssembly".
[Visual Basic] Imports System Imports System.Runtime.Remoting Public Class MyType Inherits MarshalByRefObject Public Sub New() Console.Write("Created an instance of MyType in an AppDomain with the ") Console.WriteLine("hashcode {0}", AppDomain.CurrentDomain.GetHashCode()) Console.WriteLine("") End Sub 'New Public Function GetAppDomainHashCode() As Integer Return AppDomain.CurrentDomain.GetHashCode() End Function 'GetAppDomainHashCode End Class 'MyType Class Test Public Shared Sub Main() Console.WriteLine("The hash code of the default AppDomain is {0}.", AppDomain.CurrentDomain.GetHashCode()) Console.WriteLine("") ' Creates another AppDomain. Dim domain As AppDomain = AppDomain.CreateDomain("AnotherDomain", Nothing, CType(Nothing, AppDomainSetup)) ' Creates an instance of MyType defined in the assembly called ObjectHandleAssembly. Dim obj As ObjectHandle = domain.CreateInstance("ObjectHandleAssembly", "MyType") ' Unwrapps the proxy to the MyType object created in the other AppDomain. Dim testObj As MyType = CType(obj.Unwrap(), MyType) If RemotingServices.IsTransparentProxy(testObj) Then Console.WriteLine("The unwrapped object is a proxy.") Else Console.WriteLine("The unwrapped object is not a proxy!") End If Console.WriteLine("") Console.Write("Calling a method on the object located in an AppDomain with the hash code ") Console.WriteLine(testObj.GetAppDomainHashCode()) End Sub 'Main End Class 'Test [C#] 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()); } } [C++] #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()); }
[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button
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Requirements
Namespace: System.Runtime.Remoting
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family
Assembly: Mscorlib (in Mscorlib.dll)