ASP.NET MVC: ModelState vs. ModelStateDictionary <p>I have a service which has a method that's called when a certain controller method is triggered.</p> <p>My service returns a custom result object <em>PlacementResult</em> in which I want to communicate errors that may have happened (validation) back to the controller method.</p> <p>Should <em>PlacementResult</em> have a ModelState or a ModelStateDictionary to communicate errors back to the controller (and finally view)? How would I string this together?</p> <p>Finally, how do I get the ModelState/ModelStateDictionary (whichever you tell me I should choose) back into the view (highlighting the appropriate text box, show the error message etc.)?</p> <p>Thank you !</p>