public string WebServerTest(string PostData)

        {

            PostData = "jsonData=" + PostData;

            string POSTURL = "http://101.201.78.100:8888/ChannelWebService.asmx/CheckIsConnected";

            Encoding myEncoding = Encoding.GetEncoding("UTF-8"); ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3; //将提交的字符串数据转换成字节数组 //注意提交的编码,这里默认的是Default：系统当前编码

            byte[] postData = myEncoding.GetBytes(PostData); //设置提交的相关参数

            HttpWebRequest request = WebRequest.Create(POSTURL) as HttpWebRequest; //实例化一个证书

            //X509Certificate2 cerCaiShang = GetCertificate(); ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, sslPolicyErrors) => true;

            //request.ClientCertificates.Add(cerCaiShang);

            request.Method = "POST"; request.KeepAlive = true;

            //request.AllowAutoRedirect = true;

            request.ProtocolVersion = HttpVersion.Version10;

            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;

            request.ContentType = "text/xml;charset=utf-8";

            request.ContentType = "application/x-www-form-urlencoded";

            request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)";

            CookieContainer cookieContainer = new CookieContainer();

            request.CookieContainer = cookieContainer;

            request.ContentLength = postData.Length;

            #region 传输数据

            try { using (Stream writer = request.GetRequestStream()) { writer.Write(postData, 0, postData.Length); } }

            catch (Exception ex) { return ex.Message; }

            #endregion

            #region 接收返回的数据

            string srcString = string.Empty; try { HttpWebResponse response = request.GetResponse() as HttpWebResponse; using (Stream sr = response.GetResponseStream()) { using (StreamReader reader = new StreamReader(sr, myEncoding)) { srcString = reader.ReadToEnd(); } } }

            catch (Exception ex) { return ex.Message; }

            #endregion

            return srcString;

        }