c# - returnUrl always null even when getting the login page -

i see has been asked quite lot solution posting form. i'm not getting value when redirecting custom login page. here's logincontroller

// get: /login     [allowanonymous]     public actionresult index(string returnurl)     {         viewbag.returnurl = returnurl;         return view();     } 

web.config

<authentication mode="forms">   <forms loginurl="~/login" timeout="2880" cookieless="usecookies"/> </authentication> 

and custom userauthorize filter

public override void onauthorization(authorizationcontext filtercontext)     {         // if authorized, handle accordingly         if (this.authorizecore(filtercontext.httpcontext))         {             base.onauthorization(filtercontext);         }         else         {             // otherwise redirect specific authorized area             filtercontext.result = new redirectresult("~/login");         }     } 

thanks

if using custom authorizing method, must addreturnurl parameter manually. normally, formsauthentication class handles adding parameter querystring.

var request = filtercontext.httpcontext.request;  // return url if exist if (request.httpmethod.equals("get", system.stringcomparison.currentcultureignorecase))     returnurl = request.rawurl;  filtercontext.result = new redirecttorouteresult(new routevaluedictionary(          new          {                controller = "login",                action = "index",                returnurl = returnurl,          }));