title: Problem with custom controller factory
body: <p>I've recently added Microsoft Unity to my MVC3 project and now I'm getting this error:</p>
  
  <blockquote>
    <p>The controller for path '/favicon.ico' could not be found or it does not implement IController.</p>
  </blockquote>
  
  <p>I do not really have a favicon.ico so I have no idea where that's coming from. And the weirdest thing is that the view is actually being rendered and THEN this error is being thrown... I am not sure if it's something wrong with my controller factory class because I got the code from some tutorial (I'm not to IoC - this is the first time I do that). Here's the code:</p>
  
  <p>public class UnityControllerFactory : DefaultControllerFactory
  {
      IUnityContainer container;</p>
  
  <pre><code>public UnityControllerFactory(IUnityContainer _container)
  {
      container = _container;
  }
  
  protected override IController GetControllerInstance(System.Web.Routing.RequestContext requestContext, Type controllerType)
  {
      IController controller;
  
      if(controllerType == null)
          throw new HttpException(404, string.Format("The controller for path '{0}' could not be found or it does not implement IController.",
              requestContext.HttpContext.Request.Path));
  
      if(!typeof(IController).IsAssignableFrom(controllerType))
          throw new ArgumentException(string.Format("Type requested is not a controller: {0}",
                                                              controllerType.Name),
                                                              "controllerType");
      try
      {
          controller = container.Resolve(controllerType) as IController;
      }
      catch (Exception ex)
      {
          throw new InvalidOperationException(String.Format(
                                  "Error resolving controller {0}",
                                  controllerType.Name), ex);
      }
      return controller;
  }
  </code></pre>
  
  <p>}</p>
  
  <p>Any suggestions?</p>
  
  <p>Thanks in advance!</p>