Generic Service Contract

Question

I need to have a generic Service contract but if I do that I receive this error:

[ServiceContract]
public interface IService<T> where T : MyClass
{
    [OperationContract]
    void DoWork();
}

The contract name 'x.y' could not be found in the list of contracts implemented by the service 'z.t'.

Did you change the error message? – Nix Jun 02 '11 at 15:48 — Nix, Jun 02 '11 at 15:48
Yes but the concept is the same. Thanks. – user758977 Jun 02 '11 at 15:50 — user758977, Jun 02 '11 at 15:50
I don't believe that a service contract can be generic. – John Saunders Jun 02 '11 at 15:50 — John Saunders, Jun 02 '11 at 15:50
I disagree, I have done this before. – Nix Jun 02 '11 at 17:20 — Nix, Jun 02 '11 at 17:20

score 0 · Answer 1 · answered Nov 19 '14 at 14:17

If you use an servicereference on thee client side generic will fail.

Use the following on client side with generic:

var myBinding = new BasicHttpBinding();
var myEndpoint = new EndpointAddress("");
var myChannelFactory = new ChannelFactory<IService>(myBinding, myEndpoint);
IService gks = myChannelFactory.CreateChannel();

score 0 · Accepted Answer · answered Jun 02 '11 at 16:09

As long as you use a closed generic for your interface it does work - see below. What you cannot do is to have an open generic as the contract type.

public class StackOverflow_6216858_751090
{
    public class MyClass { }
    [ServiceContract]
    public interface ITest<T> where T : MyClass
    {
        [OperationContract]
        string Echo(string text);
    }
    public class Service : ITest<MyClass>
    {
        public string Echo(string text)
        {
            return text;
        }
    }
    static Binding GetBinding()
    {
        BasicHttpBinding result = new BasicHttpBinding();
        //Change binding settings here
        return result;
    }
    public static void Test()
    {
        string baseAddress = "http://" + Environment.MachineName + ":8000/Service";
        ServiceHost host = new ServiceHost(typeof(Service), new Uri(baseAddress));
        host.AddServiceEndpoint(typeof(ITest<MyClass>), GetBinding(), "");
        host.Open();
        Console.WriteLine("Host opened");

        ChannelFactory<ITest<MyClass>> factory = new ChannelFactory<ITest<MyClass>>(GetBinding(), new EndpointAddress(baseAddress));
        ITest<MyClass> proxy = factory.CreateChannel();
        Console.WriteLine(proxy.Echo("Hello"));

        ((IClientChannel)proxy).Close();
        factory.Close();

        Console.Write("Press ENTER to close the host");
        Console.ReadLine();
        host.Close();
    }
}

Of note: http://stackoverflow.com/questions/1735035/c-sharp-generics-open-and-closed-constructed-types — Bruno Brant, May 16 '13 at 02:35

score 0 · Answer 3 · answered Jun 02 '11 at 17:04

0

Your service contract is not interoperable. It's not possible to expose generics like that via WSDL.

Take a look at this article (link) for a possible workaround.

answered Jun 02 '11 at 17:04

Tad Donaghe

6,625
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What if all the clients connected to this service are .Net ones? does the other person care about interop? This could be for an internal app and therefore not needed to be interoperable. Bad answer IMO – War Aug 14 '14 at 12:19

Generic Service Contract

3 Answers3

Linked