404 page for an ASP.NET MVC application - asp.net-mvc-3

Question

This must be simple and already answered, but I've wasted many hours on it. I can't figure how to get an error page on mistyped address. Also I'd prefer not to redirect, but to keep the URL. I've tried many combinations of CustomErrors, HttpErrors and Application_Error, but nothing works for non-existent controller - depending on HttpErrors I always get IIS 404.0 page or just an empty 404 response. Running on IIS 7.5, MVC 3.

Answer 1

I don't remember where I got the solution. But here is the code to handle the error:
First, you create a ErrorController:
public class ErrorController : Controller
{
//
// GET: /Error/
public ActionResult Index()
{
return RedirectToAction("Index", "Home");
}
public ActionResult Generic()
{
Exception ex = null;
try
{
ex = (Exception)HttpContext.Application[Request.UserHostAddress.ToString()];
}
catch { }
return View();
}
public ActionResult Error404()
{
return View();
}
}
Second, open Global file and add the following code:
protected void Application_Error(object sender, EventArgs e)
{
Exception ex = Server.GetLastError();
Application[HttpContext.Current.Request.UserHostAddress.ToString()] = ex;
}
Third, change customerror in your webconfig:
<customErrors mode="Off" defaultRedirect="/Error/Generic">
<error statusCode="404" redirect="/Error/Error404"/>
</customErrors>
More: I created one more error layout. It makes things even more clear. :)
Hope this helps you.

Answer 2

I use the following route to ensure all requests not matching any other route fall there, then you can handle that case very easily:
// this route is intended to catch 404 Not Found errors instead of bubbling them all the way up to IIS.
routes.MapRoute(
"PageNotFound",
"{*catchall}",
new { controller = "Error", action = "NotFound" }
);
Map that last (include that statement after any other .MapRoute statements).