#region 发送xml文件给指定网址
        /// <summary>
        /// 发送xml文件给指定网址
        /// </summary>
        /// <param name="v_strURL">目标Url</param>
        /// <param name="v_objXMLDoc">需要发送的数据（XmlDocument格式的）</param>
        /// <returns>服务器响应</returns>
        public static XmlDocument PostXMLTransaction(string v_strURL, XmlDocument v_objXMLDoc)
        {
            //set max enough to avoid http request is used out -> avoid dead while get response
            ServicePointManager.DefaultConnectionLimit = 200;
            XmlDocument XmlResponse = null;
            HttpWebRequest req;
            HttpWebResponse rep = null;
            Stream reqStream = null;
            //创建一个流对象(用来读取响应对象的内容）
            Stream repStream = null;
            XmlTextReader objXmlReader;
            //垃圾回收
            System.GC.Collect();
            req = (HttpWebRequest)WebRequest.Create(v_strURL);
            try
            {
                # region Start HttpRequest
                byte[] bytes;
                //传递的值
                bytes = Encoding.UTF8.GetBytes(v_objXMLDoc.InnerXml);
                //传递的方法，必须要写，而已Get必须大写。
                req.Method = "POST";
                req.ContentLength = bytes.Length;
                //表头的格式必须要写,否则请求响应的页面得不到要传递的值
                req.ContentType = "text/xml;encoding='utf-8'";
                //把传递的值写到流中
                reqStream = req.GetRequestStream();
                reqStream.Write(bytes,0,bytes.Length);
                //必须要关闭请求
                reqStream.Close();
                #endregion End HttpRequest
                //创建一个响应对象，并从请求对象中得到响应对象的事例。
                rep = (HttpWebResponse)req.GetResponse();//此时程序才开始向目标网页发送Post请求  
                //rep = req.GetResponse() as HttpWebResponse;
                #region Start HttpResponse 
                //HttpStatusCode.OK,指示请求成功，且请求的信息包含在响应中
                if (rep.StatusCode == HttpStatusCode.OK)
                {
                    //得到回应过来的流
                    repStream = rep.GetResponseStream();
                    //Load response stream into XMLReader
                    objXmlReader = new XmlTextReader(repStream);
                    XmlDocument xmldoc = new XmlDocument();
                    xmldoc.Load(objXmlReader);
                    XmlResponse = xmldoc;
                    objXmlReader.Close();
                }
                //响应关闭，要不会占用网络资源
                rep.Close();
                #endregion
            }
            catch (WebException we)
            {
               //异常处理
            }
            catch (Exception ex)
            {
                //异常处理
            }
            finally
            {
                //关闭连接
                reqStream.Close();
                repStream.Close();
                rep.Close();
                //释放对象
                objXmlReader = null;
                reqStream = null;
                repStream = null;
                rep = null;
                //objHttpWebRequest = null;
                if (req!= null)
                {
                    req.Abort();
                }
            }
            return XmlResponse;
        }
        #endregion