Question

This is what i use to implement an Dependency Injection in my MVC3 project,

public class NinjectControllerFactory : DefaultControllerFactory
{
    private readonly IKernel _ninjectKernel;
    public NinjectControllerFactory()
    {
        _ninjectKernel = new StandardKernel();
        AddBindings();
    }
    protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
    {
        return controllerType == null ? null : (IController)_ninjectKernel.Get(controllerType);
    }

    private void AddBindings()
    {
        _ninjectKernel.Bind<IUserRepository>().To<UserRepository>().InSingletonScope();            
    }
}

but i have a huge problem i want to use an Generic Handler an ".ashx" to implement my logic.

But i get an exception because the httphandler is not a Controller.

here is the exception:

    Server Error in '/' Application.
The IControllerFactory 'Infrastructure.NinjectFactory.NinjectControllerFactory' did not return a controller for the name 'registercustomer.ashx'.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: The IControllerFactory 'Infrastructure.NinjectFactory.NinjectControllerFactory' did not return a controller for the name 'registercustomer.ashx'.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[InvalidOperationException: The IControllerFactory 'Infrastructure.NinjectFactory.NinjectControllerFactory' did not return a controller for the name 'registercustomer.ashx'.]
   System.Web.Mvc.MvcHandler.ProcessRequestInit(HttpContextBase httpContext, IController& controller, IControllerFactory& factory) +422803
   System.Web.Mvc.<>c__DisplayClass6.<BeginProcessRequest>b__2() +49
   System.Web.Mvc.<>c__DisplayClassb`1.<ProcessInApplicationTrust>b__a() +13
   System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) +7
   System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +22
   System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Func`1 func) +124
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +98
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +50
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8971636
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.547 

Now is the question: How do i implement the work around this bug, to me to be able to an HttpHandler and still remain using the Ninject in my project?

Thanks in advance.

Answer 1

Due to the HttpHandler being created by the framework and there is no hook or factory method to intercept the creation of the ashx file, ninject is not able to create this object.

However you can use service locator calls or property injection from the ashx to request dependancies from the ashx code. But as far as I know, the ashx must have a default constructor, and you can then either resolve the dependancies from inside the constructor (or anywhere really) via service locator (less preferred method) or via property injection simply like this:

public class Handler
{
    [Inject]
    public IService Service { get; set; }
}

EDIT: also, to tell mvc to not process the ashx file you need to add this to ignore the route:

routes.IgnoreRoute("{resource}.ashx/{*pathInfo}");