public static string HttpRequest(string url, string method, string args, string postData = "", string encoding = "utf-8")
        {
            HttpWebRequest _request = null;
            HttpWebResponse _response = null;
            StreamReader _reader = null;

            try
            {
                if (url.IndexOf("?") == -1)
                    url = url + "?" + args;
                else
                    url = url.Substring(0, url.IndexOf("?") - 1) + "?" + args;

                _request = (HttpWebRequest)WebRequest.Create(url);
                if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
                {
                    ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
                    ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
                    _request.ProtocolVersion = HttpVersion.Version10;
                }
                _request.Method = method;

                if (method.ToLower() == "post")
                {
                    using (Stream requestStream = _request.GetRequestStream())
                    {
                        byte[] postDataBytes = Encoding.GetEncoding(encoding).GetBytes(postData);
                        requestStream.Write(postDataBytes, 0, postDataBytes.Length);
                    }
                }

                _response = (HttpWebResponse)_request.GetResponse();
                _reader = new StreamReader(_response.GetResponseStream(), Encoding.GetEncoding(encoding));

                return _reader.ReadToEnd();

            }
            catch (Exception ex)
            {
                throw new Exception("HttpRequest Error:" + ex.Message);
            }
            finally
            {
                _request = null;
                if (_response != null)
                {
                    _response.Close();
                    _reader.Dispose();
                }
            }
        }