I have a WFC(4.0) service dll for which I have to create a host application. The dll is pretty simple and has the following interfaces:

    [ServiceContract(CallbackContract=typeof(IChatServiceCallback))]
    public interface IService {
        [OperationContract]
        Guid Subscribe();
    }

    public interface IServiceCallback {
         void NotifyClient(strign message);
    }

My problem comes when I try to create a service. When I create a channel from the client to the host, I get the following exception: "The InstanceContext provided to the ChannelFactory contains a UserObjecct that does not implement the CallbackContractType 'Client.MyServiceReference.IServiceCallback'."

I found that in the ServiceReference object browser the ClientObject does not contain the IServiceCallback interface. Here my correspoding host code:

    ServiceHost host = new ServiceHost(typeof(ChatService));

    try
    {
        host.BeginOpen(new AsyncCallback(OnOpen), host);
        mre.WaitOne();
        if (host.State == CommunicationState.Opened)
        {
            Console.WriteLine("Server is running!\nServer listens on the following endpoints:");
            foreach (var endp in host.Description.Endpoints)
            {
                Console.WriteLine("\t{0}", endp.Address);
            }

            Console.WriteLine("Press <Enter> to stop the server...");
            Console.ReadLine();
            host.Close();
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine("Error: {0}", ex.Message);
    }

How can I create a host application for a Service dll which contains callback interface that is implemented on the client side?

ClientSide: try { clientID = client.Subscribe(); <-- Throws exception. } catch(Exception ex) { MessageBox.Show(ex.Message, "Error", MessageBoxButton.OK); }

• wcf
• c#-4.0
• .net-4.0

Can you use the service contract assembly directly on the client? If so you can use DuplexChannelFactory and avoid the client-side service reference code altogether.

And example here

I know this doesn't answer your question but it may help you work around it.