asp.net记住我功能

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：

 <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Login.aspx.cs" Inherits="RememberMe.Login" %>

 <!DOCTYPE html>

 <html xmlns="http://www.w3.org/1999/xhtml">
 <head runat="server">
     <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
     <title></title>
     <script type="text/javascript">
         window.onload = function () {
             document.getElementById('btnClose').onclick = function () {
                 window.close();
             };
         };
     </script>
 </head>
 <body>
     <form id="form1" runat="server">
         <div style="text-align: center;">
             <table>
                 <tr>
                     <td>用户名：
                         <input type="text" name="txtName" value="<%=uName %>" /></td>
                 </tr>
                 <tr>
                     <td>密&nbsp;&nbsp;&nbsp;&nbsp;码：<input type="password" name="txtPwd" value="<%=pwd %>" />
                     </td>
                 </tr>
                 <tr>
                     <td colspan="2">
                         <input type="checkbox" name="rememberMe" value="1" checked="checked" />记住我</td>
                 </tr>
                 <tr>
                     <td colspan="2">
                         <input type="submit" value="登录" />
                         <input type="button" value="关闭" id="btnClose" /></td>
                 </tr>
             </table>

         </div>
     </form>
 </body>
 </html>

Login.aspx

后台代码：

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Web.UI;
 using System.Web.UI.WebControls;

 namespace RememberMe
 {
     public partial class Login : System.Web.UI.Page
     {
         protected string uName;
         protected string pwd;
         protected void Page_Load(object sender, EventArgs e)
         {

             if (Request.Cookies["user"] != null)
             {
                 uName = Request.Cookies["user"].Values["n"];
                 pwd = Request.Cookies["user"].Values["p"];
             }
             if (IsPostBack)
             {
                 string userName = Request.Form["txtName"];
                 string userPwd = Request.Form["txtPwd"];
                 if (!string.IsNullOrEmpty(Request.Form["rememberMe"]))
                 {
                     if (userName == "admin" && userPwd == "admin")
                     {
                         AlertAndRedirect("Index.aspx?n=" + userName, "登录成功");
                         HttpCookie cookie = new HttpCookie("user");
                         cookie["n"] = userName;
                         cookie["p"] = userPwd;
                         cookie.Expires = DateTime.Now.AddDays();
                         Response.Cookies.Add(cookie);
                     }
                     else
                     {
                         AlertAndRedirect("Login.aspx", "登录失败");
                         Response.Cookies["user"].Expires = DateTime.Now.AddDays(-);
                     }
                 }
                 else
                 {
                     Response.Cookies["user"].Expires = DateTime.Now.AddDays(-);
                     if (userName == "admin" && userPwd == "admin")
                     {
                         AlertAndRedirect("Index.aspx?n=" + userName, "登录成功");
                     }
                     else
                     {
                         AlertAndRedirect("Login.aspx", "登录失败");
                     }
                 }
             }

         }
         private void AlertAndRedirect(string redirectURL, string msg)
         {
             Response.Write("<script>alert('" + msg + "');window.location.href='" + redirectURL + "';</script>");
         }
     }
 }

Login.aspx,cs

基本功能实现。下载：http://www.cnblogs.com/wolf-sun/admin/Files.aspx