MVC 3 wildcard route ie www.mydomain.com/username - asp.net

Question

I would like to create a simple route which will allow me to have ONLY one item listed after the base URL (other than when it's a controller), and for that item to be passed into a controller as a parameter. for example:
www.mydomain.com/user1
www.mydomain.com/user2
www.mydomain.com/user3
www.mydomain.com/user3
where user1, user2 etc are usernames and are being passed dynamically, ie i don't want to have to create a controller for each username.
naturally i would want to make sure if something like this is possible that it wont cause conflicts with other genuine controller names, thus i guess the other controllers would have to have rules created specifically for them and listed above the wildcard route
i'm not sure how to do this as i guess the first item after the slash is usually a controller.
any ideas how to tackle this?
the examples i provided may seem ambiguous, when i put www.mydomain.com/user1 etc it represents that it could be anything (ie a username),for example, www.mydomain.com/jsmith, www.mydomain.com/djohnson, www.mydomain.com/sblake, www.mydomain.com/fheeley
the idea is that a users profile can be looked up simply by entering the domain name then a fwd slash and the username.

Answer 1

ASP.Net MVC routes are process from the top down, and as soon as a match is found it won't look any further for a match. So put your most specific routes first, and your wildcard route last. If none of the specific routes match, control will be passed to the wildcard route.

Answer 2

Use a route definition such as
routes.MapRoute("{username}", new { controller = "User", action = "View"});
in your global.asax.cs file but put it last in your list of route definitions.
MVC processes your route mappings from top to bottom, so put your most general route mappings at the top, and your more specific ones at the bottom.
After you do this you will need the corresponding controller/action so create a new Controller named "UsersController" with an action named "View", like as follows:
using System.Web.Mvc;
namespace Routes.Controllers
{
public class UsersController : Controller
{
//
// GET: /{username}
public ActionResult List(string username)
{
// Get User from database/repository and pass to view
var user = ...;
return View(user);
}
}
}

Answer 3

You have to do following thing.
Create one controller or Action for Handle above scenario. For example controller="Home" and Action="GetUser"
public ActionResult GetUser(string username){
// do your work
}
In Global.asax ( Top route)
// Look at point 3 for UserNameConstraint
route.MapRoute("UserRoute" , "{username}" , new { controller="Home" , action="GetUser" } , new { username = new UserNameConstraint() });
// Put your default route after above here
Now for Create Route constraint.
Hope this help you.
public class UserNameConstraint : IRouteConstraint
{
public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
List<string> userName = GetUserName from DB
userName.Contain(values[parameterName].ToString());
}
}

Answer 4

Create a route like as follows,
routes.MapRoute(
"DefaultWithUser", // Route name
"{user}/{controller}/{action}/{id}", // URL with parameters
new { user=UrlParameter.Optional, controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);