.NetCore 2.x on using {*catchAll} routing URL.Action always returns null

Question

I am using this route to map all routes which were not found:

routes.MapRoute(
    name: "NotFound",
    template: "{*url}",
    defaults: new { controller = "Home", action = "NotFound" }
);

The problem I encountered is that @Url.Action() always returns null on this route.

Could someone explain why is this happening and what could be alternatives to this?

Answer 1

After playing around, I found a "cheat" way to do it and it kinda works. If I get NotFound page then I redirect back to the same page if Url.Action() == null

if(this._urlService.Action() == null) //same urlHelper action, only has default Home page values passed into method
{
    var query = string.Empty;
    if(Request.QueryString.HasValue)
    {
        query = Request.QueryString.Value;
    }
    var path = "/Home/NotFound" + query;
    path = string.Concat("/", this._userIdentity.CurrentLanguage.ToString().ToLower(), path);
    return base.Redirect(path);
 }

It could be because I use /{culture}/{Controller}/{Action} as my main route. Creating other test project, where my main route is default /{Controller}/{Action} has no problem at all finding the Url.Action() on NotFound page