Question

I’ve just switched Dependency Injection frameworks from Ninject to StructureMap – due to Ninject producing abysmally bad performance!

Problem I’m having is that when I wire up the DependencyResolver, my hubs are being cleared out by the RouteTable.Routes.MapHubs line:

GlobalHost.DependencyResolver = new SignalRDependencyResolver(ObjectFactory.Container);
RouteTable.Routes.MapHubs(GlobalHost.DependencyResolver);

Meaning the hubs object in the /SignalR/hubs javascript file has an empty Hubs object.

I’m assigning the DependencyResolver in application_start like in the wiki, and I’m doing my MVC4 and WebAPI Dependency Resolvers AFTER SignalR’s.

What could be causing this?

Update – here is the DependencyResolver Implementation:

public class SignalRDependencyResolver : DefaultDependencyResolver
    {
        private IContainer _container;

        public SignalRDependencyResolver(IContainer container)
        {
            _container = container;
        }

        public override object GetService(Type serviceType)
        {
            object service = null;
            if (!serviceType.IsAbstract && !serviceType.IsInterface && serviceType.IsClass)
            {
                // Concrete type resolution
                service = _container.GetInstance(serviceType);
            }
            else
            {
                // Other type resolution with base fallback
                service = _container.TryGetInstance(serviceType) ?? base.GetService(serviceType);
            }
            return service;
        }

        public override IEnumerable<object> GetServices(Type serviceType)
        {
            var objects = _container.GetAllInstances(serviceType).Cast<object>();
            objects.Concat(base.GetServices(serviceType));
            return objects;
        }
    }

Answer 1

Here is the Dependency Resolver Implementation that worked in the end:

public class SignalRDependencyResolver : SignalR.DefaultDependencyResolver
{
    private readonly IContainer _container;

    public SignalRDependencyResolver(IContainer container)
    {

        if (container == null)
        {
            throw new ArgumentNullException("container");
        }

        _container = container;
    }

    public override object GetService(Type serviceType)
    {
        var instance = _container.TryGetInstance(serviceType) ?? base.GetService(serviceType);
        return instance;
    }

    public override IEnumerable<object> GetServices(Type serviceType)
    {
        IEnumerable<object> instances =  _container.GetAllInstances(serviceType).Cast<object>();
        IEnumerable<object> instances2 = base.GetServices(serviceType);

        return instances2.Concat(instances);
    }
}