底层连接已关闭：服务器违反了协议。 FTP

Question

我正在使用下面的代码上传我的文件，它工作正常，但有时它会抛出此错误“底层连接已关闭：服务器违反协议”并停止进程，当我再次运行它时，它会上传文件解决任何问题。

我注意到的一件事，如果我运行此过程来上传多个文件，那么有时我会收到此错误，如果我执行的文件少于 5 个，那么它工作正常，知道我必须在哪里查看它。

我在谷歌上搜索，没有找到可靠的解决方案，甚至一个 msdn 博客说它是 FTPwebrequest 中的一个错误，但不确定。

环境：C# 4.0，IIS FTP 服务器。

提前致谢

                FileInfo fileInf = new FileInfo(filename);
                FtpWebRequest reqFTP;

                // Create FtpWebRequest object from the Uri provided
                reqFTP = (FtpWebRequest)FtpWebRequest.Create
                         (new Uri(path + fileInf.Name));


                // Provide the WebPermission Credintials
                 reqFTP.Credentials = new NetworkCredential(user, pwd);

                // By default KeepAlive is true, where the control connection
                // is not closed after a command is executed.
                reqFTP.KeepAlive = false;


                // Specify the command to be executed.
                reqFTP.Method = WebRequestMethods.Ftp.UploadFile;

                // Specify the data transfer type.
                reqFTP.UseBinary = true;
                reqFTP.Timeout = -1;
                reqFTP.UsePassive = true;


                // Notify the server about the size of the uploaded file
                reqFTP.ContentLength = fileInf.Length;

                // The buffer size is set to 2kb
                int buffLength = 4096;
                byte[] buff = new byte[buffLength];
                int contentLen;

                // Opens a file stream (System.IO.FileStream) to read the file
                // to be uploaded
                FileStream fs = fileInf.OpenRead();


                try
                {
                    // Stream to which the file to be upload is written
                    Stream strm = reqFTP.GetRequestStream();

                    // Read from the file stream 2kb at a time
                    contentLen = fs.Read(buff, 0, buffLength);

                    // Till Stream content ends
                    while (contentLen != 0)
                    {
                        // Write Content from the file stream to the FTP Upload
                        // Stream
                        strm.Write(buff, 0, contentLen);
                        contentLen = fs.Read(buff, 0, buffLength);
                    }

                    // Close the file stream and the Request Stream
                    strm.Close();
                    fs.Close();
                }

回答

reqFTP.KeepAlive = false;为“真”以消除我的错误。

Answer 1

从 reqFTP.KeepAlive = false 更改；到“reqFTP.KeepAlive = True;”摆脱错误