ASP.NET MVC 3 “Preview 1” includes several new ActionResult
types and corresponding helper methods.
The new HttpNotFoundResult class is used to indicate that a
resource requested by the current URL was not found. It returns a 404 HTTP
status code to the calling client. You can optionally use the new
HttpNotFound() helper method on Controller to return an instance of this action
result type, as shown in the following example:
The HttpRedirectResult class has a new Boolean “Permanent”
property that is used to indicate whether a permanent redirect should occur. A
permanent redirect uses the HTTP 301 status code. In conjunction with
this change, the Controller class now has three new methods for performing
permanent redirects: RedirectPermanent(), RedirectToRoutePermanent(), and
RedirectToActionPermanent(). These methods return an instance of
HttpRedirectResult with the Permanent property set to true.
The new HttpStatusCodeResult class can be used to set an
explicit response status code and description.