求救，HttpWebRequest登录成功后，成功获取Cookies，但操作下一步现在错误error^调用ESB服务失败!

使用登录后，并用语句
myHttpWebResponse.Cookies = CookieArray.GetCookies(myRequest.RequestUri);
MessageBox.Show("cc" + CookieArray.GetCookies(myRequest.RequestUri)[0].ToString());
检查显示了Cookies 成功获取
但登录成功用同样的语句检查Cookies 是否传过去，
myHttpWebResponse.Cookies = CookieArray.GetCookies(myRequest.RequestUri);
MessageBox.Show("cc2" + CookieArray.GetCookies(myRequest.RequestUri)[0].ToString());
检查显示了Cookies 是同一个成功传到下一步，但post下一步老是出错，显示：“error^调用ESB服务失败!”
一直找不到原因，请大家帮帮忙
代码：
byte[] byteRequest = Encoding.Default.GetBytes(postData);

                httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);
                httpWebRequest.CookieContainer = cookieContainer;
                httpWebRequest.ContentType = contentType;
                httpWebRequest.ServicePoint.ConnectionLimit = maxTry;
                httpWebRequest.Referer = url;
                httpWebRequest.Accept = accept;
                httpWebRequest.UserAgent = userAgent;
                httpWebRequest.Method = isPost ? "POST" : "GET";
                httpWebRequest.ContentLength = byteRequest.Length;
                httpWebRequest.Proxy = proxy;
                Stream stream = httpWebRequest.GetRequestStream();
                stream.Write(byteRequest, 0, byteRequest.Length);
                stream.Close();
                MessageBox.Show("cc2" + cookieContainer.GetCookies(httpWebRequest.RequestUri)[0].ToString());
                httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                Stream responseStream = httpWebResponse.GetResponseStream();
                StreamReader streamReader = new StreamReader(responseStream, encoding);
                string html = streamReader.ReadToEnd();
                streamReader.Close();
                responseStream.Close();
                currentTry = 0;

                httpWebRequest.Abort();
                httpWebResponse.Close();

                return html;
c# 模拟登录 HttpWebRequest ESB Cookie --------------------编程问答-------------------- 自己顶一下，帮帮忙啊

补充：.NET技术 ,  C#