登录页面的记住我功能

  

不能用session的原因：sessionID是以cookie的形式存在浏览器端的内存中  如果用户把浏览器关闭 则sessionID就消失    

但是服务器端的session在过期时间内还是存在的 等到浏览器在 默认的过期时间内（20分钟）不在向服务器发送请求 则过了20分钟 session销毁！

前端简单模拟：

1 <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Login.aspx.cs" Inherits="RememberMe.Login" %> 2  3  4  5  6  7     
        8      9     16 17 18     
       
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用户名：23 
密    码：27 
31 记住我
35 36 
39 40         
        
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42 43 

后台代码：

1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.Web.UI; 6 using System.Web.UI.WebControls; 7  8 namespace RememberMe 9 {10     public partial class Login : System.Web.UI.Page11     {12         protected string uName;13         protected string pwd;14         protected void Page_Load(object sender, EventArgs e)15         {16 17             if (Request.Cookies["user"] != null)18             {19                 uName = Request.Cookies["user"].Values["n"];20                 pwd = Request.Cookies["user"].Values["p"];21             }22             if (IsPostBack)23             {24                 string userName = Request.Form["txtName"];25                 string userPwd = Request.Form["txtPwd"];26                 if (!string.IsNullOrEmpty(Request.Form["rememberMe"]))27                 {28                     if (userName == "admin" && userPwd == "admin")29                     {30                         AlertAndRedirect("Index.aspx?n=" + userName, "登录成功");31                         HttpCookie cookie = new HttpCookie("user");32                         cookie["n"] = userName;33                         cookie["p"] = userPwd;34                         cookie.Expires = DateTime.Now.AddDays(7);35                         Response.Cookies.Add(cookie);36                     }37                     else38                     {39                         AlertAndRedirect("Login.aspx", "登录失败");40                         Response.Cookies["user"].Expires = DateTime.Now.AddDays(-1);41                     }42                 }43                 else44                 {45                     Response.Cookies["user"].Expires = DateTime.Now.AddDays(-1);46                     if (userName == "admin" && userPwd == "admin")47                     {48                         AlertAndRedirect("Index.aspx?n=" + userName, "登录成功");49                     }50                     else51                     {52                         AlertAndRedirect("Login.aspx", "登录失败");53                     }54                 }55             }56 57         }58         private void AlertAndRedirect(string redirectURL, string msg)59         {60             Response.Write("");61         }62     }63 }

基本功能实现。下载：