title: How add HttpContext.Current.Request.UserLanguage to the RouteValueDictionary() as default culture
body: <p>How can I add default culture to the RouteValueDictionary(): r.Defaults.Add("culture", "sv") in this code:</p>
  
  <pre><code>routes.MapRoute(
              name: "Default",
              url: "{controller}/{action}/{id}",
              defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
              );
  
          foreach(var r in from Route r in routes where !(r.RouteHandler is SingleCultureRouteHandler) select r)
          {
              r.RouteHandler = new MultiCultureRouteHandler();
  
              r.Url = "{culture}/" + r.Url;
  
              // Adding default culture
              if(r.Defaults == null)
              {
                  r.Defaults = new RouteValueDictionary();
              }
              r.Defaults.Add("culture", "sv");
  
              // Adding constraint for culture param
              if(r.Constraints == null)
              {
                  r.Constraints = new RouteValueDictionary();
              }
              r.Constraints.Add("culture", new UserRouteConstraint("en", "sv"));
          }
  </code></pre>
  
  <p>This way: <code>r.Defaults.Add("culture", HttpContext.Current.Request.UserLanguages[0].Substring(0, 2))</code> get this error message: "Request is not available in this context".</p>
  
  <p>Thanks in advance!</p>