WCF Service - runtime not seeing the ServiceContract on Interface

Question

I'm new to WCF and trying to get my first service running. I'm close but stuck on this problem.

In my interface definition file, I have this:

[ServiceContract(Namespace="http://mysite.com/wcfservices/2009/02")]       
    public interface IInventoryService
    {
        [OperationContract]
        string GetInventoryName(int InventoryID);
    }

Then I have my class file (for the service) that inherits it:

   public class InventoryService : IInventoryService
    {
        // This method is exposed to the wcf service
        public string GetInventoryName(int InventoryID)
        {
            return "White Paper";
        }

Finally, in my Host project I have this:

    ServiceHost host = new ServiceHost(typeof(Inventory.InventoryService));
    host.AddServiceEndpoint(typeof(Inventory.InventoryService), new NetTcpBinding(),
        "net.tcp://localhost:9000/GetInventory");
    host.Open();

Everything compiles fine, and when the host goes to add the service endpoint, it bombs with this: "The contract type Inventory.InventoryService is not attributed with ServiceContractAttribute. In order to define a valid contract, the specified type (either contract interface or service class) must be attributed with ServiceContractAttribute."

I know I'm missing something simple here. I have the interface clearly marked as a service contract and there's a reference to that project in the Host project.

Valenza

Answer 1

ServiceHost host = new ServiceHost(typeof(Inventory.InventoryService));
host.AddServiceEndpoint(typeof(Inventory.InventoryService), new NetTcpBinding(),
    "net.tcp://localhost:9000/GetInventory");
host.Open();

If your ServiceContract attribute is on the Interface not the concrete class, try the following:

ServiceHost host = new ServiceHost(typeof(Inventory.InventoryService));
host.AddServiceEndpoint(typeof(Inventory.IInventoryService), new NetTcpBinding(),
    "net.tcp://localhost:9000/GetInventory");
host.Open();

Tweed

When I try that it gives me the ArgumentException, "ServiceHost only supports class service types." – Valenza

Switched the wrong one - change the AddServiceEndpoint call to interface, keep ServiceHost as class. – Gilly

Got it! So I'm instantiating ServiceHost, passing in the concrete class, but I'm defining the endpoint, or binding, with the interface, which is really the contract definition (i.e. not the class). I'll eventually get the hang of this. Thanks Brian and Andrew. – Valenza