Seems No Controllers Recognized by my controller factory

Question

I want to create a controllerfactory with Autofac but I've got null reference instance error in this line : string ctrName = contr.ControllerContext.RouteData.Values["Controller"].ToString() when I run my project.

This is my controller factory:

internal class ControllerFactory : DefaultControllerFactory
{
    private readonly Dictionary<string, Func<RequestContext, IController>> _controllerMap;

    public ControllerFactory()
    {
        List<IController> lstControllers = DependencyResolver.Current.GetServices<IController>().ToList();
        _controllerMap = new Dictionary<string, Func<RequestContext, IController>>();

        foreach (Controller contr in lstControllers)
        {
            string ctrName = contr.ControllerContext.RouteData.Values["Controller"].ToString();  //iv got null instance error in this line
            _controllerMap.Add(ctrName, c => contr);
        }
    }

    public override IController CreateController(RequestContext requestContext, string controllerName)
    {

        if (_controllerMap.ContainsKey(controllerName))
        {
            return _controllerMap[controllerName](requestContext);
        }
        else
            throw new KeyNotFoundException(controllerName);
    }
}

and this is my appstart:

        protected void Application_Start()
    {

        var builder = new ContainerBuilder();

        builder.RegisterControllers(typeof(MvcApplication).Assembly).AsImplementedInterfaces();

        builder.Register(s => new ControllerFactory()).As<IControllerFactory>();


        var container = builder.Build();
        DependencyResolver.SetResolver(new AutofacDependencyResolver(container));


        AreaRegistration.RegisterAllAreas();
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        BundleConfig.RegisterBundles(BundleTable.Bundles);
    }

Error reason is clear: ControllerContext of my foreach item is null...but why? I have controller in my solution:

   public class HomeController : Controller 
{
    public ActionResult Index()
    {
        return View();
    }

    public ActionResult About()
    {
        ViewBag.Message = "Your application description page.";

        return View();
    }

    public ActionResult Contact()
    {
        ViewBag.Message = "Your contact page.";

        return View();
    }

}

Update: I inspected debugger on foreach..the item type is WebApplication1.Controllers.HomeController means exactly my home controller but controller context of mt item is null !!!

Answer 1

This means the earliest point at which you can access the ControllerContext property is by overriding the Execute or Initialize method (but calling base.Execute or base.Initialize first):

protected override void Execute(RequestContext requestContext)
{
  base.Execute(requestContext);

  // .ControllerContext is available from this point forward.
}

protected override void Initialize(RequestContext requestContext)
{
  base.Initialize(requestContext);

  // .ControllerContext is available from this point forward.
}

The latter (Initialize) is the absolute earliest point at which you can use the ControllerContext property, unless you handled the assignment yourself, which is not recommended (as parts of the framework will be dependent on having that property assigned to at that time).

Source: Null ControllerContext in my custom controller inheriting from BaseController

You are going to have to map your Controllers elsewhere based on this new information.