How can I get controller type and action info from a url or from route data?

Here is the solution I compiled from various sources. The url variable should contain the URL of the action:

        url = "YOUR URL";
        // Original path is stored and will be rewritten in the end
        var httpContext = new HttpContextWrapper(HttpContext.Current);
        string originalPath = httpContext.Request.Path;

        try
        {
            // Fake a request to the supplied URL into the routing system
            httpContext.RewritePath(url);
            RouteData urlRouteData = RouteTable.Routes.GetRouteData(httpContext);

            // If the route data was not found (e.g url leads to another site) then authorization is denied.
            // If you want to have a navigation to a different site, don't use AuthorizationMenu
            if(urlRouteData != null)
            {
                string controllerName = urlRouteData.Values["controller"].ToString();
                string actionName = urlRouteData.Values["action"].ToString();

                // Get an instance of the controller that would handle this route
                var requestContext = new RequestContext(httpContext, urlRouteData);
                var controllerFactory = ControllerBuilder.Current.GetControllerFactory();
                var controller = (ControllerBase) controllerFactory.CreateController(requestContext, controllerName);

                // Find the action descriptor
                var controllerContext = new ControllerContext(httpContext, new RouteData(), controller);
                var controllerDescriptor = new ReflectedControllerDescriptor(controller.GetType());
                var actionDescriptor = controllerDescriptor.FindAction(controllerContext, actionName);
            }
        }
        finally
        {
            // Reset our request path.
            httpContext.RewritePath(originalPath);
        }

public Type ControllerType(string controllerName)
{
   var fullName = controllerName + "Controller";
   var assemblyName = Assembly.GetExecutingAssembly().FullName;
   return Activator.CreateInstance(assemblyName, fullTypeName).GetType();
}

public MethodInfo ActionMethodInfo(string actionName, Type controllerType)
{
   return controllerType.GetMethod(actionName);
}

Are you thinking of an implementation similar to this? Some Try/Catches required!

  protected override void OnActionExecuting(ActionExecutingContext filterContext)
  {
     var type1 = filterContext.Controller.GetType();
     var type2 = filterContext.ActionDescriptor
                    .ControllerDescriptor.ControllerType;
  }

OK, sorry, I missed the "root" part.

Then, another way, you can save controller type to thread storage. Pseudocode:

  protected override void OnActionExecuting(ActionExecutingContext filterContext)
  {
     if (!Thread.LocalStorage.Contains("root_controller"))
        Thread.LocalStorage["root_controller"] = 
            filterContext.ActionDescriptor
                    .ControllerDescriptor.ControllerType;
  }

Just an idea. I'm sure thread local storage is available in C#. The key idea here is that you save it only for first request, thus it's always root controller.