asp.net mvc4 过滤器的简单应用：登录验证

直接上代码，不要说话。

ASP.NET MVC4过滤器的简单应用：验证登录

    [AcceptVerbs(HttpVerbs.Post)]
         public ActionResult login(FormCollection form)
         {
             Session["login"] = "True";
             return Redirect("/Home/Index");

         }

         [IsLogin]
         public ActionResult Index()
         {
             return View();
         }

   //自定义过滤器
     public class IsLogin : ActionFilterAttribute
     {
         //当方法执行时
         public override void OnActionExecuting(ActionExecutingContext filterContext)
         {
             //base.OnActionExecuting(filterContext);
             try
             {  var sess=filterContext.RequestContext.HttpContext.Session["login"];
                 if (sess==null  ||sess.ToString()!="True")
                     filterContext.Result = new RedirectResult("/Home/login");
             }
             catch
             {
                 filterContext.Result = new RedirectResult("/Shared/Error");
             }
         }

         //当方法执行完毕
         public override void OnActionExecuted(ActionExecutedContext filterContext)
         {
             base.OnActionExecuted(filterContext);
         }
     }