HttpWebRequest 请求网页为什么拿不到返回cookie？求解啊！
为什么cookieContainer里面没有抓包工具抓到的cookie（roll_t_hd_thda=760bb74a5a0ee393bf73b70a3aa48cc2）呢？
代码：

StreamReader sr = null;

            HttpWebResponse response = null;

            HttpWebRequest request = null;

            Encoding encoding = System.Text.Encoding.GetEncoding("UTF-8");

            CookieContainer cookieContainer = new CookieContainer();

            Stream outstream = null;

            Stream instream = null;

            string content;

            string roll = "http://tc.hd.xiaomi.com/hdget?callback=hdcontrol";

            request = WebRequest.Create(roll) as HttpWebRequest;

            request.CookieContainer = cookieContainer;

            request.Method = "GET";           

            request.Host = "tc.hd.xiaomi.com";

            request.UserAgent = "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.11 Safari/537.36";

            response = (HttpWebResponse)request.GetResponse();

            instream = response.GetResponseStream();

            sr = new StreamReader(instream, encoding);



            content = sr.ReadToEnd();

            Uri urroll = new Uri(roll);



            if ((cookieContainer.GetCookieHeader(urroll).IndexOf("roll_t_hd_thda") < 0 ))

            {