ASP.NET MVC: Route with optional parameter, but if supplied, must match \d+

Question

I\'m trying to write a route with a nullable int in it. It should be possible to go to both /profile/ but also /profile/\\d+.

route         


        

Answer 1

It's possible something changed since this question was answered but I was able to change this:

routes.MapPageRoute(
    null,
    "projects/{operation}/{id}",
    "~/Projects/ProjectWizard.aspx",
    true,
    new RouteValueDictionary(new
    {
        operation = "new",
        id = UrlParameter.Optional
    }),
    new RouteValueDictionary(new
    {
        id = new NullableExpressionConstraint(@"\d+")
    })
);

With this:

routes.MapPageRoute(
    null,
    "projects/{operation}/{id}",
    "~/Projects/ProjectWizard.aspx",
    true,
    new RouteValueDictionary(new
    {
        operation = "new",
        id = UrlParameter.Optional
    }),
    new RouteValueDictionary(new
    {
        id = @"\d*"
    })
);

Simply using the * instead of the + in the regular expression accomplished the same task. The route still fired if the parameter was not included, but if included it would only fire if the value was a valid integer. Otherwise it would fail.