MVC实现登陆与退出登陆

/// <summary>
        /// 退出登陆
        /// </summary>
        /// <returns></returns>
        public ActionResult ExitLogin()
        {
            Session["uinfo"] = null;

            return View("~/Views/login/Login.cshtml");
        }

        /// <summary>
        /// 验证登陆
        /// </summary>
        /// <returns></returns>
        
        [HttpPost]
        public ActionResult ExeLogin(string username, string password)
        {
            //取出用户输入的用户名与密码
            //string username = Request["username"];
            //string password = Request["password"];

            UserDAL ud = new UserDAL();

           Users us = ud.Login(username, password);

           if (us == null)//登陆失败
           {
               Response.Write("登陆失败......");
                return View("~/Views/login/Login.cshtml");
           }
           else
           {
               //用户的信息存储在Session里边
               Session["uinfo"] = us;

              //登陆成功跳转到首页
             return RedirectToAction("Index","home");
           }

            
        }