MVC route attribute exclude id - asp.net-mvc

Question

I have Home controller and Details action which received int id parameter.
I want map "/" url to Home controller, Details action, id = 1.
Also I want map urls like "/st15" to Home controller, Details action, id = 15.
So I wrote following attributes
[Route("~/{id:int:min(1):max(1)=1}")]
[Route("st{id:int:min(2)}")]
public ActionResult Details(int id)
{...}
The problem is url "/1" is also mapping to this action, but I need 404 for it

Answer 1

I would recommend leveraging the RouteConfig.cs file that is created with default MVC projects in VS2012.
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapRoute(
name: "Details",
url: "/st{id}",
defaults: { controller = "Home", action = "Details", id = "1" }
);
routes.MapRoute(
name: "Default",
url: "/",
defaults: new { controller = "Home", action = "Details", id = "1" }
);
}
This will try to match urls to those two designated routes in the order you add them to your RouteConfig file. Since the 'Default' route doesn't have any additional parameters on its URL definition, a call to "/1" won't match a route and you'll get a 404.
If you used a blank project, adding a RouteConfig file is a trivial matter. Just add a RouteConfig.cs file and define the class to contain the RegisterRoutes method I listed, then in your Global.asax file's Application_Start function, add a line for
RouteConfig.RegisterRoutes(RouteTable.Routes);
And you'll be good to go.
(EDIT)
I'm not certain that there still won't be conflicts, but you can combine Attribute routing with the standard routing paradigm by simply adding
routes.MapMvcAttributeRoutes();
to your RegisterRoutes function, immediately after the IgnoreRoute call, and the application will always defer to your Route attributes first, then check the defined routes.
However, since you've indicated you'd like to avoid using the standard routing approach altogether, you could simply define the attributes to take the following routes:
[Route("~/")]
[Route("st{id:int:min(2)}")]
public ActionResult Details (int id = "1")
{...}
To set a default value for the id parameter and avoid trying to handle the case in the attribute itself. Since you define a minimum value for the {id} parameter in your second Route attribute, you shouldn't have to worry about the case of "/st" trying to route to that action. It wouldn't match either defined route and so would 404.