Question

我创建了一个ftp客户端，它在白天连接了几次，从FTP服务器检索日志文件。

问题是，几个小时后我收到来自FTP服务器的错误消息（达到-421会话限制..）。当我检查与netstat的连接时，我可以看到几个＆＃39; ESTABLISHED＆＃39;即使我已关闭＆＃34;已连接到服务器连接。

当我尝试在命令行或FileZilla上执行相同操作时，连接已正确关闭。

ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + remoteFile);
ftpRequest.Credentials = new NetworkCredential(user, pass);
ftpRequest.UseBinary = true;
ftpRequest.UsePassive = true;
ftpRequest.KeepAlive = true;
ftpRequest.Method = WebRequestMethods.Ftp.DownloadFile;
ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
ftpStream = ftpResponse.GetResponseStream();
FileStream localFileStream = new FileStream(localFile, FileMode.Create);
int bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
/* Resource Cleanup */

localFileStream.Close();
ftpStream.Close();
ftpResponse.Close();
ftpRequest = null;

如何正确关闭/断开连接？我忘了什么吗？

Answer 1

尝试将FtpWebRequest.KeepAlive属性设置为false。如果KeepAlive设置为false，则在请求完成时将关闭与服务器的控制连接。

ftpWebRequest.KeepAlive = false;

Answer 2

您是否尝试将回复包装在using语句中？

using (FtpWebResponse response = request.GetResponse() as FtpWebResponse)
        {
            using (Stream responseStream = response.GetResponseStream())
            {
                using (StreamReader streamReader = new StreamReader(responseStream))
                {
                    string responseString = streamReader.ReadToEnd();

                    Byte[] buffer = Encoding.UTF8.GetBytes(responseString);
                    memoryStream = new MemoryStream(buffer);
                }

                responseStream.Close();
            }
            response.Close();
        }

如何使用FtpWebRequest正确断开与FTP服务器的连接

2 个答案: