Recaptcha PostAsync 抛出 System.Net.WebException：底层连接已关闭

如何解决Recaptcha PostAsync 抛出 System.Net.WebException：底层连接已关闭

尝试实施谷歌 Recaptcha，在本地运行良好。但是当部署到其他服务器（通过八达通）时，它会抛出异常。无法找到原因。发生在 PostAsync 调用上。请需要帮助。

  using (HttpClient client = new HttpClient())

{
                System.Net.ServicePointManager.SecurityProtocol = System.Net.ServicePointManager.SecurityProtocol | System.Net.SecurityProtocolType.Tls12;
                client.Timeout = TimeSpan.FromMilliseconds(this.ValidationTimeoutMiliseconds);                    



                var values = new Dictionary<string,string>
                {
                   { "secret",Secret },{ "response",value as string }
                };



                LogHelper.WriteLog("Start: Recaptcha requestdata is about to post to google...");
                var response = client.PostAsync("https://www.google.com/recaptcha/api/siteverify",new FormUrlEncodedContent(values)).GetAwaiter().GetResult();
                LogHelper.WriteLog("End: Recaptcha requestdata is posted successfully");



                var responseString = response.Content.ReadAsstringAsync().Result;
                var responseModel = JsonConvert.DeserializeObject<GRecaptchaValidationResponseModel>(responseString);



                if (responseModel.ErrorCodes != null && responseModel.ErrorCodes.Contains("invalid-input-secret"))
                    LogHelper.WriteLogAsync("Invalid input secret for reCaptcha. Please configure in advanced settings parameters for Forms.");



                return responseModel.Success;
 }

抛出异常： 发布到 google recaptcha 时发生异常：System.Net.WebException：底层连接已关闭：发送时发生意外错误。 ---> System.IO.IOException: 无法从传输连接读取数据：远程主机强行关闭了现有连接。 ---> System.Net.sockets.socketException: 一个现有的连接被远程主机强行关闭 在 System.Net.sockets.socket.EndReceive(IAsyncResult asyncResult) 在 System.Net.sockets.NetworkStream.EndRead(IAsyncResult asyncResult) --- 内部异常堆栈跟踪结束 --- 在 System.Net.Tlsstream.EndWrite(IAsyncResult asyncResult) 在 System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar) --- 内部异常堆栈跟踪结束 --- 在 System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult,TransportContext& context) 在 System.Net.Http.httpclienthandler.GetRequestStreamCallback(IAsyncResult ar)

解决方法

谢谢 已解决，服务器中存在防火墙问题阻止。解决后，工作正常。