15.6.2 Defining Optional URL Segments; Listinig 15-19. Specifying an Optional URL Segment in the RouteConfig.cs File

UrlsAndRoutes/UrlsAndRoutes/App_Start/RouteConfig.cs

@@ -12,7 +12,7 @@ namespace UrlsAndRoutes
         public static void RegisterRoutes(RouteCollection routes)
         {
             routes.MapRoute("MyRoute", "{controller}/{action}/{id}",
-                new { controller = "Home", action = "Index", id = "DefaultId" });
+                new { controller = "Home", action = "Index", id = UrlParameter.Optional});
         }
     }
 }