Question

I’ve implemented my first WCF application.
I need one method IConsoleData GetData();
I receive CommunicationException "There was an error reading from the pipe: The channel was closed. (109, 0x6d)." in client.

When I replaced IConsoleData GetData(); to string GetData(); application become functionable.

How should I fix the code to use IConsoleData GetData()?

Server:

//public interface IConsoleData
//{
//    double GetCurrentIndicator();
//}

//public class IConsoleDataImpl : IConsoleData
//{
//    public double GetCurrentIndicator()
//    {
//        return 22;
//    }
//}

[ServiceContract]
public interface IMBClientConsole
{
    [OperationContract]
    //IConsoleData GetData();
    string GetData();
}

public class MBClientConsole : IMBClientConsole
{
    //public IConsoleData GetData()
    //{
    //    return new IConsoleDataImpl();
    //}
    public string GetData()
    {
        //return new IConsoleDataImpl();
        return "hello";
    }
}

class Log
{

    private ServiceHost _host;

    public void initialize()
    {
        _host = new ServiceHost(typeof (MBClientConsole),
                                new Uri[]
                                    {
                                        new Uri("net.pipe://localhost")
                                    });
            _host.AddServiceEndpoint(typeof(IMBClientConsole),
              new NetNamedPipeBinding(),
              "PipeReverse");

            _host.Open();
            System.Threading.Thread.Sleep(1000000);
            // TODO: host.Close();
    }
}

Client:

//public interface IConsoleData
//{
//    double GetCurrentIndicator();
//}

[ServiceContract]
public interface IMBClientConsole
{
    [OperationContract]
    //IConsoleData GetData();
    string GetData();
}

class Program
{
    static void Main(string[] args)
    {
        ChannelFactory<IMBClientConsole> pipeFactory =
            new ChannelFactory<IMBClientConsole>(
                new NetNamedPipeBinding(),
                new EndpointAddress(
                    "net.pipe://localhost/PipeReverse"));

        IMBClientConsole pipeProxy =
          pipeFactory.CreateChannel();

        while (true)
        {
            string str = Console.ReadLine();
            Console.WriteLine("pipe: " +
              //pipeProxy.GetData().GetCurrentIndicator());
              pipeProxy.GetData());
        }
    }
}

Answer 1

if you use an Interface you have to do two things:

1. the implementations needs to be serializable (use the DataContract – Attribute)
2. you have to tell the service the known types if you use the interface (here it’s IConsoleDataImpl)

Make your live easier and decorate the implementation with DataContract and the members of it with DataMember Attributes and use the implementation instead of the interface.

You can find a lot about this here

(and don’t begin the implementations name with “I”)

here is a rework without the known-type stuff and I think this will help you for your
first steps – no need to dig in that deep (Interfaces + KnownTypes) yet.

[DataContract]
public class ConsoleData
{
    [DataMember]
    public double CurrentIndicator
    {
        get { return 22; }
        set { /* whatever */ }
    }
}

[ServiceContract]
public interface IMBClientConsole
{
    [OperationContract]
    ConsoleData GetData();
}