cookie小记

清除cookie可用下面2种的方法。注意如果要清除的cookie的域是指定的，则这里也应该指定,否则无效
                1:
                Response.Cookies["mycookiename"].Expires = DateTime.Now.AddDays(-1);
                Response.Cookies["mycookiename"].Domain = ".test.com";

2:              
                HttpCookie cookies = new HttpCookie("mycookiename", null);
                cookies.Domain = ".test.com";
                cookies.Expires = new DateTime(1900, 1, 1);
                Response.Cookies.Add(cookies);

3：

HttpCookie us = Request.Cookies["user"];
                if (us != null)
                {
                //会让指定有效期的cookie变成会话cookie,要等关闭浏览器该cookie才消失
                us.Values.Remove("username");
                Response.AppendCookie(us);
                }

4、

HttpCookie cookie = new HttpCookie("mycookiename2", cookievalue);
               cookie.HttpOnly = true; //设置后客户端能看到,js无法访问到，js也无法修改名为mycookiename的值
               cookie.Domain = ".test.com";
               Response.Cookies.Add(cookie);