ObjectHandle Classe

Definição

public ref class ObjectHandle : MarshalByRefObject, System::Runtime::Remoting::IObjectHandle

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDual)]
public class ObjectHandle : MarshalByRefObject, System.Runtime.Remoting.IObjectHandle

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDual)]
[System.Runtime.InteropServices.ComVisible(true)]
public class ObjectHandle : MarshalByRefObject, System.Runtime.Remoting.IObjectHandle

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDual)>]
type ObjectHandle = class
    inherit MarshalByRefObject
    interface IObjectHandle

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDual)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type ObjectHandle = class
    inherit MarshalByRefObject
    interface IObjectHandle

Public Class ObjectHandle
Inherits MarshalByRefObject
Implements IObjectHandle

Herança

Object

MarshalByRefObject

ObjectHandle

Atributos

ClassInterfaceAttribute ComVisibleAttribute

Implementações

IObjectHandle

Exemplos

O seguinte exemplo de código mostra como criar um objeto noutro AppDomain, e recuperar um proxy para o objeto a partir de um ObjectHandle. Neste exemplo, pode assumir que o código da MyType classe é compilado numa assembly chamada "ObjectHandleAssembly".

using namespace System;
using namespace System::Runtime::Remoting;
public ref class MyType: public 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( "" );
   }

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

};

int 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", nullptr, (AppDomainSetup^)nullptr );
   
   // Creates an instance of MyType defined in the assembly called ObjectHandleAssembly.
   ObjectHandle^ obj = domain->CreateInstance( "ObjectHandleAssembly", "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( "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 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());
   }
}

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
   
   
   Public Function GetAppDomainHashCode() As Integer
      Return AppDomain.CurrentDomain.GetHashCode()
   End Function 'GetAppDomainHashCode

End Class


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

End Class

Observações

A ObjectHandle classe é usada para passar um objeto (num estado enrolado) entre múltiplos domínios de aplicação sem carregar os metadados do objeto enrolado em cada AppDomain um por onde o ObjectHandle veículo passa. Assim, a ObjectHandle classe dá ao chamador o controlo de quando o Type objeto remoto é carregado num domínio.