ASP.NET MVC Session 过期验证跳转至登入页面

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace TaskManagement.Controllers
{
    public class CheckLoginController : Controller
    {
        /// <summary>
        /// 实现统一登录验证检查
        /// </summary>
        /// <param name="filterContext"></param>
        protected override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            //如果没有设置Session值那么就跳转到登入页面
            //实现登录检查
            if (Session["userinfo"] == null)
            {
                //RedirectResult tourl = new RedirectResult("/Login/UserLogin"); 
                //filterContext.Result = tourl;
                ContentResult Cr = new ContentResult
                {
                    Content = string.Format("<script type=‘text/javascript‘>top.location.href=‘{0}‘;</script>", "/Login/UserLogin")
                };
                filterContext.Result = Cr;
            }
        }
    }
}