Question

I’m trying to use route constraints in an Asp.Net MVC Application.

routes.MapRoute(     'theRoute',     'MyAction/{page}',     new { controller = 'TheController', action = 'MyAction', page = 1 },     new { page = @'[0-9]' }); 

When I enter an url like ~/MyAction/aString, an YSOD is shown with an invalid operation exception. What can I do to redirect invalid url to the 404 page?

I know I can solve the issue with a string parameter in the controller action and int.TryParse, but then the route constaint is useless.

How can I choose the exceptiontype that is thrown by the route constraints?

Answer 1

The problem is that you do not have a route that matches the route that ends in a string.

Modify your routes similar to:

routes.MapRoute(     'Default',                                              // Route name     '{controller}/{action}/{id}',                           // URL with parameters     new { controller = 'Home', action = 'Index', id = 0 },     new { id = '[0-9]' }// Parameter defaults ); routes.MapRoute(     'Default2',                                              // Route name     '{controller}/{action2}/{sid}',                           // URL with parameters     new { controller = 'Home', action = 'Index2', sid = '' }  // Parameter defaults ); 

and modify your controller

public ActionResult Index(int id)     {         ViewData['Title'] = 'Home Page';         ViewData['Message'] = 'Welcome to ASP.NET MVC! Your id is: '+ id.ToString();          return View();     }      public ActionResult Index2(string sid)     {         ViewData['Title'] = 'Home Page 2.'+sid.ToString();         ViewData['Message'] = 'Welcome to ASP.NET MVC! \'' + sid.ToString() +'\' is an invalid id';          return View('index');     } 

now when you pass a string for the ID, Index2 will be called and you can do whatever you need to do to handle the incorrect parameter.