How to: Create an Instance of a Client-Activated Type

This topic is specific to a legacy technology that is retained for backward compatibility with existing applications and is not recommended for new development. Distributed applications should now be developed using the  Windows Communication Foundation (WCF).

This article shows two ways of instantiating a client-activated object. The first method uses CreateInstance, the second uses the new operator.

Create an instance using Activator.CreateInstance

1. Create and register a TcpChannel

   Dim channel As TcpChannel = New TcpChannel()
    ChannelServices.RegisterChannel(channel, False)
   

   TcpChannel channel = new TcpChannel();
   ChannelServices.RegisterChannel(channel, false);
   

2. Register the client-activated object

   RemotingConfiguration.RegisterActivatedClientType( _
       GetType(MyRemoteObject), _
       "tcp://localhost:1234/MyServer")
   

   RemotingConfiguration.RegisterActivatedClientType(
       typeof(MyRemoteObject),
       "tcp://localhost:1234/MyServer");
   

3. Call CreateInstance

   Dim url() As Object = {New UrlAttribute("tcp://localhost:1234/Server")}
   Dim obj As MyRemoteObject = CType(Activator.CreateInstance( _
       GetType(MyRemoteObject), _
       Nothing, _
       url), MyRemoteObject)
   

   object[] url = { new UrlAttribute("tcp://localhost:1234/Server") };
   MyRemoteObject obj = (MyRemoteObject)Activator.CreateInstance(
       typeof(MyRemoteObject),
       null,
       url);
   

Create an Instance using the New Operator

1. Create and register a channel

   Dim channel As TcpChannel = New TcpChannel()
    ChannelServices.RegisterChannel(channel, False)
   

   TcpChannel channel = new TcpChannel();
   ChannelServices.RegisterChannel(channel, false);
   

2. Register the client-activated object

   RemotingConfiguration.RegisterActivatedClientType( _
       GetType(MyRemoteObject), _
       "tcp://localhost:1234/MyServer")
   

   RemotingConfiguration.RegisterActivatedClientType(
       typeof(MyRemoteObject),
       "tcp://localhost:1234/MyServer");
   

3. Call the new operator

   Dim obj As MyRemoteObject = New MyRemoteObject(123)
   

   MyRemoteObject obj = new MyRemoteObject(123);
   

Example

The following code illustrates both methods of creating a client-activated instance:

Imports System
Imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
Imports System.Runtime.Remoting.Channels.Tcp
Imports System.Runtime.Remoting.Activation
Imports Server

Module Client

    Sub Main()
        ' Create and register a channel
        Dim channel As TcpChannel = New TcpChannel()
        ChannelServices.RegisterChannel(channel, False)

  ' Register the client activated object
        RemotingConfiguration.RegisterActivatedClientType( _
            GetType(MyRemoteObject), _
            "tcp://localhost:1234/MyServer")

  ' Call Activator.CreateInstance
    Dim obj As MyRemoteObject = CType(Activator.CreateInstance( _
       GetType(MyRemoteObject), _
       Nothing, _
           url), MyRemoteObject)
   
        ' OR call operator new
        Dim obj As MyRemoteObject = New MyRemoteObject(123)

        Console.WriteLine("Client.Main(): GetValue returned: {0}", obj.GetValue())
        Console.WriteLine("Client.Main(): Calling SetValue(10)")
        obj.SetValue(10)
        Console.WriteLine("Client.Main(): GetValue returned: {0}", obj.GetValue())
    End Sub

End Module

using System;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Activation;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Tcp;
using Server;

namespace Client
{
    class Client
    {
        static void Main(string[] args)
        {
// Create and register channel
            TcpChannel channel = new TcpChannel();
            ChannelServices.RegisterChannel(channel, false);

// Register client activated object
            RemotingConfiguration.RegisterActivatedClientType(
                typeof(MyRemoteObject),
                "tcp://localhost:1234/MyServer");

// Call Activator.CreateInstance
object[] url = { new  UrlAttribute("tcp://localhost:1234/Server") };
         MyRemoteObject obj = (MyRemoteObject)Activator.CreateInstance(
            typeof(MyRemoteObject),
            null,
               url);
      // OR call operator new
            MyRemoteObject obj = new MyRemoteObject(123);

            Console.WriteLine("Client.Main(): GetValue returned: " + obj.GetValue());
            Console.WriteLine("Client.Main(): Calling SetValue(10)");
            obj.SetValue(10);
            Console.WriteLine("Client.Main(): GetValue returned: " + obj.GetValue());
        }
    }
}

Compiling the Code

This example requires:

• References to the System and System.Runtime.Remoting namespaces, and the namespace that implements MyRemoteObject.

See Also

Concepts

Activation of Remote Objects
Configuration of Remote Applications
Server Activation
Lifetime Leases
Client Activation