C# 伪造 referer 提交数据

private string SendRequest(string account, string cardNumber, string cardPass)
     {
         string targetUrl = https://xxx.com/;//要提交数据的目标网站

            //提交的数据
         string postData = string.Format("ursName={0}&userName2={0}&cardNo={1}&cardPass={2}", account, cardNumber, cardPass);

         HttpWebRequest request = (HttpWebRequest)WebRequest.Create(targetUrl);
         request.Method = "POST";
         request.Referer = http://www.xxx.com/jsp/xxx.jsp;
         byte[] bytes = Encoding.UTF8.GetBytes(postData);
         request.ContentType = "application/x-www-form-urlencoded";
         request.ContentLength = bytes.Length;
         Stream requestStream = request.GetRequestStream();
         requestStream.Write(bytes, , bytes.Length);

         HttpWebResponse response = (HttpWebResponse)request.GetResponse();
         StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.Default);
         string responseText = reader.ReadToEnd();

         string res = "成功！";
         if (responseText.Contains("errorID"))
         {
             string errorDetailPage = new System.Text.RegularExpressions.Regex(@"URL=(?<url>.*?)"">",
                 System.Text.RegularExpressions.RegexOptions.IgnoreCase | System.Text.RegularExpressions.RegexOptions.Multiline
                 ).Match(responseText).Groups["url"].Value;

             HttpWebRequest requestErrorInfo = (HttpWebRequest)WebRequest.Create(errorDetailPage);
             requestErrorInfo.Method = "GET";
             requestErrorInfo.Proxy = request.Proxy;
             HttpWebResponse responseErrorInfo = (HttpWebResponse)requestErrorInfo.GetResponse();
             StreamReader readerErrorInfo = new StreamReader(responseErrorInfo.GetResponseStream(), Encoding.Default);
             string responseTextErrorInfo = readerErrorInfo.ReadToEnd();
             string errorDetailMessage = new System.Text.RegularExpressions.Regex(@"<h3>(?<info>.*?)<.*?</h3>",
                 System.Text.RegularExpressions.RegexOptions.IgnoreCase | System.Text.RegularExpressions.RegexOptions.Multiline
                 ).Match(responseTextErrorInfo).Groups["info"].Value.Replace("&nbsp;", "");

             res = string.Format(@"失败！<br />错误信息：{0}<br /><a href=""{1}"" target=""_blank"">查看错误详情</a>", errorDetailMessage, errorDetailPage);
         }

         return res;
     }