客户端

 <form id="form1" runat="server">

     <div>

     用户名:<input type="text" name="txtName" /><br />

         密码:<input type="password" name="txtPwd" /><br />

         记住我:<input type="checkbox" name="checkMe" value="" />

         <input type="submit" value="登录" />

     </div>

       </form>

 服务器端

  public partial class CookieLogin : System.Web.UI.Page

     {

         protected void Page_Load(object sender, EventArgs e)

         {

             if (IsPostBack)

             {

                 CheckUserLogin();

             }

             else

             {

                 CheckCookieInfo();

             }

         }

         /// <summary>

         /// 对Cookie中存储的信息进行校验

         /// </summary>

         public void CheckCookieInfo()

         {

             if (Request.Cookies["cp1"] != null && Request.Cookies["cp2"] != null)

             {

                 string userName = Request.Cookies["cp1"].Value;

                 string userPwd = Request.Cookies["cp2"].Value;

                 //判断Cookie中存储的用户名是否正确.

                 if (userName == "itcast")

                 {

                     if (userPwd == Common.WebCommon.GetMd5String(Common.WebCommon.GetMd5String("")))

                     {

                         //给Session赋值.

                         Response.Redirect("Test.aspx");

                     }

                 }

                 Response.Cookies["cp1"].Expires = DateTime.Now.AddDays(-);

                 Response.Cookies["cp2"].Expires = DateTime.Now.AddDays(-);

             }

         }

         /// <summary>

         /// 判断用户名密码是否正确，用户登录

         /// </summary>

         public void CheckUserLogin()

         {

             string userName=Request.Form["txtName"];

             string userPwd=Request.Form["txtPwd"];

             if (userName == "itcast" && userPwd == "")

             {

                 //给Session赋值.

                 if (!string.IsNullOrEmpty(Request.Form["checkMe"]))//表示用户选择了复选框.只会将选中的复选框的值提交到服务端

                 {

                     HttpCookie cookie1 = new HttpCookie("cp1",userName);

                     HttpCookie cookie2 = new HttpCookie("cp2", Common.WebCommon.GetMd5String(Common.WebCommon.GetMd5String(userPwd)));

                     cookie1.Expires = DateTime.Now.AddDays();

                     cookie2.Expires = DateTime.Now.AddDays();

                     Response.Cookies.Add(cookie1);

                     Response.Cookies.Add(cookie2);

                 }

                 Response.Redirect("Test.aspx");

             }

         }

     }