Himall商城ExpressDaDaHelper GetResponseResult

 public static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) { return true; }
        private static string GetResponseResult(string url, string param)
        {
            string result = string.Empty;

            string strURL = url;
            try
            {
                System.Net.HttpWebRequest request;
                request = (HttpWebRequest)WebRequest.Create(strURL);
                request.Method = "POST";
                request.ContentType = "application/json;charset=UTF-8";
                string paraUrlCoded = param;
                byte[] payload;
                payload = System.Text.Encoding.UTF8.GetBytes(paraUrlCoded);
                request.ContentLength = payload.Length;
                Stream writer = request.GetRequestStream()