In a previous post I talked about using MVC’s controller injection to drop in DLLs that contain controller classes. It allows for a nice separation leading onto creating a composite UI. I was happily using this mechanism when it just refused to load a controller from an additional DLL. I still do not understand why it doesn’t work but my workaround is to override the ControllerFactory. Here is a quick example of this, please note I’ve hardcoded the condition for the sake of this example.

protected void Application_Start()         
{
  ControllerBuilder.Current.SetControllerFactory(new MyControllerFactory());
  AreaRegistration.RegisterAllAreas();
  RegisterGlobalFilters(GlobalFilters.Filters);
  RegisterRoutes(RouteTable.Routes);
} 

     
public class MyControllerFactory : System.Web.Mvc.DefaultControllerFactory
{
protected override Type GetControllerType(System.Web.Routing.RequestContext requestContext, string controllerName)         
{             
  if (controllerName == "Library")
  {                                 
    Type reflib = Type.GetType("LibraryUI.Library,LibraryUI");
    return reflib;                              
  }             
  return base.GetControllerType(requestContext, controllerName);         
  }              
} 

Note: setcontrollerfactory is a bit old school, should be using the IoC of choice…I’ll need to look into a bit more, but for now this works