c# - Url action null object asp.net mvc -

i need create global url , send email. create global url url.action url.action return me null. , don't know why. knows? have method:

public string sendrecoverymessage(users usermodel)     {         messagemodel message = new messagemodel();          string resetlink = "<a href='"                    + url.action("setnewpassword", "home", new { timelink = usermodel.timelink }, "http")                    + "'>Ссылка для восстановления пароля</a>";          message.emailto = usermodel.email;         message.emailfrom = "narkom@info.by";         message.title = "Восстановление пароля";         message.message = resetlink;          string responsetostring = sendmessage(message);          try         {             rootobject r = jsonconvert.deserializeobject<rootobject>(responsetostring);             return r.msg + "Для продолжения изменения пароля пройдите по ссылке указаной в письме. У вас есть сутки на изменение вашего пароля!";         }         catch (exception)         {             return responsetostring;         }     } 

and route:

public static void registerroutes(routecollection routes)     {         routes.ignoreroute("{resource}.axd/{*pathinfo}");          //defaulf route         routes.maproute(             name: "default",             url: "{controller}/{action}/{id}",             defaults: new { controller = "home", action = "index", id = urlparameter.optional }         );     } 

and recovery password method:

public actionresult setnewpassword(string timelink)     {         var recemaildetails = dbmodel.users.where(x => x.timelink == timelink).firstordefault();          if (recemaildetails == null)         {             viewbag.redirectmessage = "Данная ссылка больше не активна!";             return view("~/views/home/redirectpage.cshtml");         }          datetime datenow = convert.todatetime(datetime.now);         datetime dateconfirm = convert.todatetime(recemaildetails.datetime);          timespan diff = dateconfirm - datenow;          var totalseconds = math.floor(diff.totalseconds);          totalseconds += 86400;          if (totalseconds < 0)         {             viewbag.redirectmessage = "Время действия ссылки истекло. Нам очень жаль :c";             return view("~/views/home/redirectpage.cshtml");         }         else         {             session["idresetuser"] = recemaildetails.id;              changepasswordmodel cpm = new changepasswordmodel();              try             {                 recemaildetails.datetime = null;                 recemaildetails.timelink = null;                  dbmodel.savechanges();                 modelstate.clear();             }             catch (dbentityvalidationexception exc)             {                 foreach (var entityvalidationerrors in exc.entityvalidationerrors)                 {                     foreach (var validationerror in entityvalidationerrors.validationerrors)                     {                         viewbag.redirectmessage = exc.message;                     }                 }             }              return view("~/views/home/setnewpassword.cshtml", cpm);         }     } 

try -

string resetlink = "<a href='" + url.action("setnewpassword", "home", new system.web.routing.routevaluedictionary(new { timelink = usermodel.timelink }), "http", , request.url.host) + "'>Ссылка для восстановления пароля</a>";