MVC Route match based on parameter type

Question

I have a situation where I want the ThisAction controller to look like this :

public ActionResult Index()...
public ActionResult Index(int programId)...
public ActionResult Index(string programKey)...

With the goal of a route being set up like so

www.website.com/ThisAction/ <- matches first function
www.website.com/ThisAction/123 <- matches second function
www.website.com/ThisAction/ABC <- matches third function

Is this possible to set up in the global.asx route?

Answer 1

You would need to use attribute routing with route constraints to easily get that flexibility.

[RoutePrefix("ThisAction")]
public class ThisActionController : Controller {
    [HttpGet]
    [Route("")] //Matches GET ThisAction
    public ActionResult Index() {
        //...
    }
    [HttpGet]
    [Route("{programId:int}")] //Matches GET ThisAction/123
    public ActionResult Index(int programId) {
        //...
    }
    [HttpGet]
    [Route("{programKey}")] //Matches GET ThisAction/ABC
    public ActionResult Index(string programKey) {
        //...
    }    
}

Make sure that attribute routeing is enabled in RouteConfig

public class RouteConfig {
    public static void RegisterRoutes(RouteCollection routes) {
        //...other code removed for brevity

        //Attribute routes
        routes.MapMvcAttributeRoutes();

        //convention-based routes

        //...other code removed for brevity

        routes.MapRoute(
            "Default",
            "{controller}/{action}/{id}",
            new { controller = "Home", action = "Index", id = "" }
        );
    }
}

The route will work along side convention-based routing.

Just note that once you use it on a controller you have to use it on the entire controller. So the controller is either all convention-based or all attribute routing.