Ninject with WCF Duplex channel

Question

I'm using ninject with wcf to inject parameters into service classes. I now need to do this for a duplex service, and I'm unsure how to proceed.

At the moment, my client invokes the duplex service using a DuplexChannelFactory like this:

    InstanceContext instanceContext = new InstanceContext(new TheCallback());
    var factory = new DuplexChannelFactory<IScannerManager>(instanceContext, "ScannerManagerEndPoint");
    var channel = factory.CreateChannel();

IClientCallBack is part of my contract for duplex comms:

[ServiceContract(CallbackContract = typeof(IClientCallBack))]
public interface IScannerManager
{
    [OperationContract]
    void Register(string token);

}

public interface IClientCallBack
{
    [OperationContract(IsOneWay = true)]
    void SendClientMessage(ScannerMessageWrapper message);
}

I've modified my service ctor to add the new param I want to inject like this:

    public ScannerManagerService(Func<IClientCallBack> callBack, IRepositoryFactory repositoryFactory)
    { .. }

Where IRepositoryFactory is what I now want to inject. I've wired up my IRepositoryFactory in my ninject bindings, but when I test the code I see:

System.ServiceModel.FaultException`1[System.ServiceModel.ExceptionDetail] : Error activating IntPtr
No matching bindings are available, and the type is not self-bindable.
Activation path:
  3) Injection of dependency IntPtr into parameter method of constructor of type Func{IClientCallBack}
  2) Injection of dependency Func{IClientCallBack} into parameter callBack of constructor of type ScannerManagerService
  1) Request for ScannerManagerService

So ninject is saying it can't see a binding for the callback.. I can't just define a binding for the callback I presume - is this possible with ninject?

Note: This question is similar to Dependency Inject with Ninject 2.0 , but I'm asking it again because there are no accepted answers there. In that post the suggestion is made to inject a factory, but I'm unsure how that would look and if it would mean you don't need to use DuplexChannelFactory.

Thanks.

Answer 1

I'm not finding anything about the IClientCallback class online, so I'm assuming this is something specific to your product? You can certainly create a binding to the Func<IClientCallback> , or you can define a specific factory interface and bind to that instead.

Bind<Func<IClientCallback>>.To...

or

public interface IClientCallbackFactory { IClientCallback GetCallback(); }
...
Bind<IClientCallbackFactory.To...

The thing is, I don't know what you'd bind it to, because I don't know what role it plays in your application.

Update

I did a little reading up on Duplex Services , and I think this may be what you're looking for:

Bind<Func<IClientCallback>>().ToMethod(
    c => () => OperationContext.Current.GetCallbackChannel<IClientCallback>());

As I mentioned earlier, you could likewise create a factory interface that is implemented using the same method.