Question

i am beginner for WCF. so i was reading a code online for small wcf chat.i got stuck to create wcf client for that wcf chat. the url from where i was reading http://islameldemery.blogspot.in/2008/05/wcf-serverclient-chat-sample.html

there is one part for interface and service is hosted in win form with the help of ServiceHost but i am not being able to understand how proxy was created at client end.

they use this event below

InnerDuplexChannel.Opened
InnerDuplexChannel.Closed
InnerDuplexChannel.Faulted 

which i really do not understand. can anyone tell me how the client was created. please visit the url and please tell me how that person create a proxy at client side for that chat service.

i tried to create a proxy dynamically like self hosted as

var myBinding = new NetTcpBinding(SecurityMode.None);
  DuplexChannelFactory<ISampleChatCallback> cf =
          new DuplexChannelFactory<ISampleChatCallback>(
              new CallbackImpl(),
              myBinding,
              new EndpointAddress("net.tcp://192.168.1.2:8080/DataService")); 
  IServerWithCallback srv = cf.CreateChannel();

but srv has no event called Opened,Closed or faulted etc. i really need to understand how proxy was created at cleint end. please help me to create proxy as a result i can complete the code for client side. thanks

Answer 1

Have a look at the private void buttonConnect_Click(object sender, EventArgs e)

if (CheckServer()) //this seems to get metadata (MEX) from server
{
    proxy = null;
    InstanceContext context = new InstanceContext(this);

    // Step into this method and see what code gets executed.
    // This code can be generated by Visual Studio or written manually
    proxy = new Client.SampleService.SampleChatClient(context);

    proxy.InnerDuplexChannel.Opened += new EventHandler(InnerDuplexChannel_Opened);
    ...
}

The proxy exposes some events that (I suppose) are just wrappers of the WCF duplex channel communication class (whatever it is). Those events get fired when a new connection is opened, closed or appears in a faulted state.