void UpdateContactSign()         {            string ServerPage ="http://localhost/WebService/MyService.asmx";             try             {                 //ServerPage += "?op=TangramAction";                 ServerPage += "/MyAction";//MyAction是WebService中的方法            string strXml="<a ObjID=\"9\"></a>",;//第一个参数            string strData="ContactSign|990011|我的数据";//第二个参数            string res = HttpConnectToServer(ServerPage, strXml, strData);                 //MessageBox.Show(res);             }             catch (Exception ex)             {             }         }         //发送消息到服务器       public string HttpConnectToServer(string ServerPage,string strXml,string strData)         {             string postData = "strXml=" + strXml+"&strData="+strData;             byte[] dataArray = Encoding.Default.GetBytes(postData);             //创建请求             HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(ServerPage);             request.Method = "POST";             request.ContentLength = dataArray.Length;             request.ContentType = "application/x-www-form-urlencoded";             //创建输入流             Stream dataStream = null;             try             {                 dataStream = request.GetRequestStream();             }             catch (Exception)             {                 return null;//连接服务器失败             }             //发送请求             dataStream.Write(dataArray, 0, dataArray.Length);             dataStream.Close();             //读取返回消息             string res = string.Empty;             try             {                 HttpWebResponse response = (HttpWebResponse)request.GetResponse();                 StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8);                 res = reader.ReadToEnd();                 reader.Close();             }             catch (Exception ex)             {                 return null;//连接服务器失败             }             return res;         }