public static string SoapV12WebService(string URL, string MethodName, Hashtable Pars, string XmlNs)
        {
            ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);
            //System.GC.Collect();
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL);
            //System.Net.ServicePointManager.DefaultConnectionLimit = 50;
            request.Method = "POST";
            request.ContentType = "application/soap+xml; charset=utf-8";
            //request.ContentType = "text/xml; charset=utf-8";
           
            // 凭证
            request.Credentials = CredentialCache.DefaultCredentials;
            //request.Credentials = new NetworkCredential("administrator","hiip123");
            //超时时间
            request.Timeout = 10000;
            //request.ReadWriteTimeout = 30 * 1000;
            byte[] data = HashtableToSoap12(Pars, XmlNs, MethodName);
            request.ContentLength = data.Length;
            Stream writer = request.GetRequestStream();
            writer.Write(data, 0, data.Length);
            writer.Close();
            var response =request.GetResponse();//----在这个位置一直操作超时。
            XmlDocument doc = new XmlDocument();
            StreamReader sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
            string retXml = sr.ReadToEnd();
            //response.Close();
            sr.Close();
            doc.LoadXml(retXml);
            XmlNamespaceManager mgr = new XmlNamespaceManager(doc.NameTable);
            mgr.AddNamespace("soap12", "http://www.w3.org/2003/05/soap-envelope");
            string xmlStr = doc.SelectSingleNode("//soap12:Body/*/*", mgr).InnerXml;
            return xmlStr;
        }