How can we make an ASP.NET MVC4 route based on a subdomain?

Question

How can we make an ASP.NET MVC4 route that uses subdomain information to determine its route? For example:

website1.domain.com goes to domain.com\

Answer 1

ASP.NET's built-in routing doesn't directly support sub-domain routing. But fortunately, there's AttributeRouting, which is a very popular add-on library for routing that allows you to do lots of fancy routing, including sub-domain routing.

Here's an example from the Attribute Routing site:

[RouteArea("Users", Subdomain = "users")]
public class SubdomainController : Controller
{
    [GET("")]
    public ActionResult Index() { /* ... */ }
}