ASP.NET Routing Constraint For Specific URL

I have an asp.net application where I need to have a general route for given Medical Specialties to route to a given page except for one which I want to route to a different page.

For example I want /Specialties/Allergy, /Specialties/Nutrition to all route to a given page like they currently do. The part I can't figure out is I want the URL to still show /Specialties/Urology but have urology rout to a different page because it is becoming essentially it own subsite where the other ones are not.

I'm sure I need to add a Route constraint but I can't seem to figure out how to accomplish that.

I have include all of the relevant code I currently use for the general route.

private static void AddEntityRoute(string name, string url, string path, string dir)
{
((List<string>)HttpContext.Current.Application["RouteList"]).Add(url);

RouteTable.Routes.Add(name,
 new Route(url, new EntityRouteHandler(path, dir)));
}

public class EntityRouteHandler : IRouteHandler
{
    string _virtualPath;
    private readonly string baseDir;

    public EntityRouteHandler(string virtualPath, string baseDir)
    {
        _virtualPath = virtualPath;
        this.baseDir = baseDir;
    }

    public IHttpHandler GetHttpHandler(RequestContext requestContext)
    {
        var display = BuildManager.CreateInstance开发者_如何转开发FromVirtualPath(
                        _virtualPath, typeof (Page)) as IEntityDisplay;

        display.FriendlyURL = baseDir + requestContext.RouteData.Values["name"];
        return display;
    }
}

AddEntityRoute("Specialties", "Specialties/{name}", "~/SpecialtyDisplay.aspx", "/Specialties/");

You're approaching this the wrong way.

If your intention is to direct a specific url to a different controller/action, then just add another route.

routes.MapRoute("", "Specialties/Urology", new { controller = "someothercontroller", action = "someotheraction" });
routes.MapRoute("", "Specialties/{speciality}", new { controller = "specialities", action = "show" });

Here a request to "Specialities/Urology" would match the first route. A request to "Specialities/Allergy" would match the second.