//设置，删除Cookie //provider jb51.net         protected void set_cookie()         {             HttpCookie UserNameCookie = Request.Cookies["UserNameCookie"];             HttpCookie UserPasswordCookie = Request.Cookies["UserPasswordCookie"];             if (this.CheSave.Checked)             {                 lblcookie.Text = "1";                 //保存用户名和密码到cookie                 if (UserNameCookie == null)                 {                     UserNameCookie = new HttpCookie("UserNameCookie");                     UserNameCookie.Values.Add("UserName", TxtUserName.Text);                     UserNameCookie.Expires = DateTime.Now.AddDays(30);                     Response.Cookies.Add(UserNameCookie);                 }                 //修改COOKIE                 else if (UserNameCookie.Values["UserName"] != TxtUserName.Text)                 {                     SetToCookie(UserNameCookie, "UserName", TxtUserName.Text);                 }                 if (UserPasswordCookie == null)                 {                     UserPasswordCookie = new HttpCookie("UserPasswordCookie");                     string password1 = FormsAuthentication.HashPasswordForStoringInConfigFile(TxtUserPassword.Text, "MD5");     //如果重新指定用户密码，则重新加密密码                     UserPasswordCookie.Values.Add("UserPassword", password1);                     UserPasswordCookie.Expires = DateTime.Now.AddDays(30);                     Response.Cookies.Add(UserPasswordCookie);                 }                 else if (UserPasswordCookie.Values["UserPassword"] != FormsAuthentication.HashPasswordForStoringInConfigFile(TxtUserPassword.Text, "MD5") && TxtUserPassword.Text != "1234567890")                  //“1234567890”是程现在密码框中的十个字符。                 {                     SetToCookie(UserPasswordCookie, "UserPassword", FormsAuthentication.HashPasswordForStoringInConfigFile(TxtUserPassword.Text, "MD5"));                 }             }             else             {                 lblcookie.Text = "0";                 //从cookie删除用户名和密码                 if (Response.Cookies["UserNameCookie"] != null)                 {                     HttpCookie myCookie = new HttpCookie("UserNameCookie");                     myCookie.Expires = DateTime.Now.AddDays(-1d);                     Response.Cookies.Add(myCookie);                 }                 if (Response.Cookies["UserPasswordCookie"] != null)                 {                     HttpCookie myCookie = new HttpCookie("UserPasswordCookie");                     myCookie.Expires = DateTime.Now.AddDays(-1d);                     Response.Cookies.Add(myCookie);                 }             }         }         //检查是否存在COOKie情况         public void check_cookie()         {             HttpCookie UserNameCookie = Request.Cookies["UserNameCookie"];             HttpCookie UserPasswordCookie = Request.Cookies["UserPasswordCookie"];             if (UserNameCookie != null)             {                 this.CheSave.Checked = true;                 TxtUserName.Text = UserNameCookie.Values["UserName"];             }             if (UserPasswordCookie != null)             {                 TxtUserPassword.Attributes.Add("value", "1234567890");//设置密码框初始值             }         }         public string getpassword()         {             HttpCookie UserPasswordCookie = Request.Cookies["UserPasswordCookie"];             string strpwd = "";  //获取此密码字符串与数据库存中的密布相比。             if (lblcookie.Text == "1")             {                 strpwd = UserPasswordCookie.Values["UserPassWord"];//直接获取COOKIE中的密码值             }             else             {                 strpwd= FormsAuthentication.HashPasswordForStoringInConfigFile(TxtUserPassword.Text, "MD5"); //对密码进行加密             }             return strpwd;  //返回密码字段            }          //修改COOKIE这段的方法         public void SetToCookie(HttpCookie httpcookie, string cookiename, string cookievalue)         {             httpcookie.Values[cookiename] = cookievalue;             httpcookie.Expires = DateTime.Now.AddDays(30);             Response.Cookies.Add(httpcookie);         }     }