Url.Action() does not remove default values

Question

I have rather a simple routing map.

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

Now, If use Url.Action("Index", "Home") , it does not properly remove defaults values of the route. And it gives me /Home/Index .

Now, if I remove either {id} or {seoName} , and its corresponding default value, then the URL is properly generated like / (root).

What I am missing here? It does not seem to be an ambient value, since I am visiting the main page with no ids, nor seoNames.

Any ideas?

Answer 1

You would need multiple mappings to achieve what you want as you are only allowed to make the last route placeholder optional.

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

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