关于指定页跳转到登陆，登陆后再跳到指定页的方法

1.判断是否登陆，如果没有登陆则跳转到登陆页

        public ActionResult Index()

        {

            if (!SignHelp.IsSign()) return ChangeResult();         

            return View();

        }





//跳到login页

        public ActionResult ChangeResult()

        {

            var returnurl = HttpUtility.UrlEncode("/visitPage/index");

            return Redirect("/login/index?returnUrl=" + returnurl);

        }

2.在登陆页取到地址，存放隐藏域

        public ActionResult Index()

        {

            string returnurl = Request.QueryString["returnUrl"];

            returnurl = HttpUtility.UrlDecode(returnurl);

            ViewBag.ReturnUrl = returnurl;

            return View();

        }

3隐藏域

 <input type="hidden" id="returnurl" value="@ViewBag.ReturnUrl" />

4.在js中进行处理

 var returnurl = $("#returnurl").val();          

 location.replace(returnurl == "" ? "/home/index" : returnurl);