C# HttpWebReqeust和HttpWebResponse发送请求

  var request = (HttpWebRequest)WebRequest.Create("URL");

            var data = Encoding.UTF8.GetBytes("username=zhenjinggu&md5Pwd=643d1820b9ce49bbf283b4875848596c&otpCode=");

            request.Method = WebRequestMethods.Http.Post;
            request.Timeout = 60 * 1000;
            request.AllowAutoRedirect = true;
            request.ContentLength = data.Length;
            request.ContentType = "application/x-www-form-urlencoded";
            request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";
            request.UserAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.86 Safari/537.36";
            var stream = request.GetRequestStream();
            stream.Write(data, 0, data.Length);
            stream.Close();

            var response = (HttpWebResponse)request.GetResponse();
            var sr = new StreamReader(response.GetResponseStream());
            var content = sr.ReadToEnd();