Question

I have a Silverlight project that uses a WCF service that I created. My problem is that in my WCF service, I created a ServiceHost but VS2010 doesn’t seem to recognize the instance of my object (underlines the svHost). Below is the code for my service.

using System;
using System.Collection.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.ServiceModel.Activation;

namespace userIO.Web
{
     [ServiceContract]
     public class CoordsService
     {
         [OperationContract]
         public double xDir();
         [OperationContract]
         public double yDir();
         [OperationContract]
         public String keyPressed();

         public class Coords : CoordsService
         {
             public double xDir { get; set; }
             public double yDir { get; set; }
             public String keyPressed { get; set; }
         }

         ServiceHost svHost = new ServiceHost(typeof(Coords), new Uri("http://localhost:8080"));
         BasicHttpBinding binding = new BasicHttpBinding();
         svHost.AddServiceEndpoint(typeof(CoordsService), binding, "");
         svHost.Open();
     }
}

Answer 1

Your ServiceContract should decorate an interface (a contract). The ServiceHost should host an instance of this interface and be outside the same service that it’s hosting. At least I’ve only seen it done in this way.

The basic structure is:

[ServiceContract]
public interface IService
{
     [OperationContract]
     void DoSomething(Data data);
}

[DataContract]
public class Data
{
     [DataMember]
     int Num {get;set;}
}

public class Service : IService
{
    public void DoSomething(Data data)
    {  // do something }
}

// run in any other kind of app, console, win service, winform/wpf
static void Main()
{
         ServiceHost svHost = new ServiceHost(typeof(Service), new Uri("http://localhost:8080"));
         BasicHttpBinding binding = new BasicHttpBinding();
         svHost.AddServiceEndpoint(binding, "");
         svHost.Open();

}

An even easier solution to get your service up and running in VS2010 is to just create the service in a new WCF Service template. Take out their demo code, put in your own code for the servicecontract interface and the implementation service, then choose debug -> run and VS2010 will host the service for you without having to create an external app to run the service. Will also let you send data to the service to test out the code and the return values of your wcf functions in their simple winforms app.