Question

I’m learning MVC 4, and it’s my understanding that going to this URL should pass an int of 44 to the Edit() method of the controller. Indeed, when I go here:

http://localhost:51921/TrackerJob/Edit/44

… this method gets invoked:

public ActionResult Edit(int trackerJobId = -1)
{
    Debug.WriteLine(trackerJobId);
}

… but the parameter is always -1. I had this working in a different project, but for some reason it’s always -1 in this project. I don’t see a difference between the two projects that would cause one to work and this one to fail. If I change the method signature to this:

public ActionResult Edit(int trackerJobId)
{
    Debug.WriteLine(trackerJobId);
}

I get an error:

The parameters dictionary contains a null entry for parameter 'trackerJobId' of non-nullable type 'System.Int32'

Any ideas? I’m not sure what to check…

Edit – Including routes, by request*

public class RouteConfig
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );

        routes.MapRoute(
            name: "Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
        );
    }
}

Answer 1

If you want to use the default routing then just make sure your parameter is called id.

Otherwise you could add a new route like this:

routes.MapRoute(
    name: "TrackerJob",
    url: "{controller}/{action}/{jobtrackerid}",
    defaults: new { controller = "TrackerJob", action = "Index", id = UrlParameter.Optional }
);

Make sure you add this route BEFORE the default route. The order of routes is very important!

Only you know if the trackerJobId is optional or not.

Note that if you want something more fancy you can tweak the routes to produce what you want.

e.g. If you want URLs like http://localhost:51921/TJ-E-44 for editing then your route would look like this:

routes.MapRoute(
    name: "TrackerJobEdit",
    url: "TJ-E-{jobtrackerid}",
    defaults: new { controller = "TrackerJob", action = "Edit", id = UrlParameter.Optional }
);

I’m sure you get the idea.