asp.net routing issue and conflict

Question

i am using asp.net routing to show some pages, but it is conflicting , the first 2 are working but the third one goes to the 2nd route eventhough i have a seperate page for it to work.

routes.MapPageRoute(
          "post",
          "{postname}-{postid}/",
          "~/post.aspx"
      );

routes.MapPageRoute(
          "Posts",
          "{Category}/{PageNo}/",
          "~/posts.aspx", true,
            new RouteValueDictionary { { "PageNo", "" } }
      );

routes.MapPageRoute(
          "News",
          "{News-Category}/{PageNo}/",
          "~/news.aspx", true,
            new RouteValueDictionary { { "PageNo", "" } }
      );

any help is appreciated

thanks

Answer 1

The Posts and News routes have exactly the same URL signature. That is, any URL with 2 segments will always match the Posts route and the News route is an unreachable execution path.

You need to either use 1 or more constant segments or 1 or more constraints to ensure there are 2-segment routes Posts and News routes can miss.

routes.MapPageRoute(
      "post",
      "{postname}-{postid}",
      "~/post.aspx"
  );

routes.MapPageRoute(
      "Posts",
      "Category/{PageNo}",
      "~/posts.aspx", true,
        new RouteValueDictionary { { "PageNo", UrlParameter.Optional } }
  );

routes.MapPageRoute(
      "News",
      "News-Category/{PageNo}",
      "~/news.aspx", true,
        new RouteValueDictionary { { "PageNo", UrlParameter.Optional } }
  );

Think of the routes like a switch case statement. If the condition matches, the route will return. But if you have 2 routes that will both match the same condition, the first one will always win and the second one will be unreachable.