/// 
        /// 提交数据请求        /// 
        /// 请求提交的地址 如：https://car.etaiping.com:6004/ecms2/portal/商户号/请求类型（接口名称）        /// 提交的数据(字符串)        /// 
             public string RequestData(string PostData)        {            string POSTURL = string.Format("https://www.sina.com.cn");            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;            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;            //request.ClientCertificates.Add(new X509Certificate("C:\\CerPath\\_Cer.cer"));//证书路径                        #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;        }