public TaskInfoUI(FileDownloadingInfo fdi)
{
IsDownloadTask = true;
FDI = fdi;
FDI.FTPDownloadingInfoNotifications += (FileDownloadingInfo source, string[] msgs) => {
if (msgs.Length > 0)
{
Message = msgs[0];
}
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Progress"));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("ProgressMsg"));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("IsIndeterminate"));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("FileSize"));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Speed"));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("TimeRemaining"));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Status"));
};
stopwatch.Start();
}
private async void DownloadRemoteFile(string remoteFileName, string localFileName)
{
if (connectionStatus != ConnectionStatus.Connected)
{
return;
}
var fdi = new FileDownloadingInfo(ftpService.Server, ftpService.CurrentRemotePath, remoteFileName, localService.CurrentLocalPath, localFileName);
TaskInfoUI tiUI = new TaskInfoUI(fdi);
fdi.Tag = tiUI;
tiUI.tokenSource = new CancellationTokenSource();
taskInfoList.Add(tiUI);
await ftpService.DownloadFile(fdi, tiUI.tokenSource.Token, DefaultFTPTaskErrorHandler);
if (fdi.IsFinished)
{
Dispatcher.Invoke(new Action(() => { RefreshLocalInfo(); }));
}
}
public Task DownloadFile(FileDownloadingInfo fileDownloadingInfo, CancellationToken token, FTPTaskErrorHandler ftpTaskErrorHandler = null)
{
return(Task.Run(() =>
{
lock (fileDownloadingInfo)
{
if (fileDownloadingInfo.IsFinished)
{
return;
}
FTPConnection ftpConnection = null;
try
{
ftpConnection = CreateConnection(fileDownloadingInfo.serverInfo);
Utils.WriteDebugInfo(ftpConnection.connectionName, "用于下载文件的连接已建立。\r\nFileDownloadingInfo: " + fileDownloadingInfo.ToString());
ftpConnection.DownloadFile(fileDownloadingInfo, token);
ftpConnection.Close();
fileDownloadingInfo.Close();
fileDownloadingInfo.IsFinished = true;
Utils.WriteDebugInfo(ftpConnection.connectionName, "操作已完成，连接主动断开。");
}
catch (OperationCanceledException)
{
ftpConnection?.Close();
if (ftpConnection != null)
{
Utils.WriteDebugInfo(ftpConnection.connectionName, "操作被用户取消，连接已断开。");
}
}
catch (FTPResponseException ex)
{
ftpTaskErrorHandler?.Invoke(ex, fileDownloadingInfo.Tag);
ftpConnection?.Close();
if (ftpConnection != null)
{
Utils.WriteDebugInfo(ftpConnection.connectionName, "由于发生了不可恢复的异常，连接已断开。" + " FTPResponseException: " + ex.Message);
}
}
}
}));
}
/// <summary>
/// 下载文件，过程可以暂停，注意：如果本地文件已存在，会覆盖对应文件，调用者应当检查文件是否已存在并给出提示
/// </summary>
public void DownloadFile(FileDownloadingInfo fdi, CancellationToken token)
{
try
{
ChangeCurrentWorkingDirectory(fdi.RemotePath);
var time = GetFileLastModifiedTime(fdi.RemoteFileName);
if (time == null)
{
throw new FTPResponseException("无法获取远程文件的最后修改日期，或该远程文件已经不存在");
}
var remote_size = GetFileSize(fdi.RemoteFileName);
if (remote_size == -1)
{
throw new FTPResponseException("无法获取远程文件的文件大小，或该远程文件已经不存在");
}
string localfile = fdi.LocalPath + (fdi.LocalPath.EndsWith("\\") ? "" : "\\") + fdi.LocalFileName;
if (remote_size == 0)
{
fdi.LocalFileStream = File.Create(localfile);
fdi.LocalFileStream.Close();
return;
}
EnterPassiveMode();
if (fdi.DownloadedBytes > 0)
{
// 尝试断点续传
if (!time.Equals(fdi.SavedLastModifiedTime) || remote_size != fdi.SavedSize)
{
fdi.Notify("远程文件在上一次暂停的传输之后已经被修改，从0开始下载");
fdi.DownloadedBytes = 0;
}
else
{
SendCommand("REST " + fdi.DownloadedBytes);
try
{
var message = ReceiveResponse(300, 350);
if (message == null)
{
throw new FTPResponseException();
}
}
catch (FTPResponseException)
{
// 服务器可能不支持REST指令
fdi.Notify("服务器不支持断点续传，从0开始下载");
fdi.DownloadedBytes = 0;
}
}
}
fdi.SavedLastModifiedTime = time;
fdi.SavedSize = remote_size;
if (fdi.DownloadedBytes == 0 && fdi.LocalFileStream != null)
{
fdi.LocalFileStream.Seek(0, SeekOrigin.Begin);
fdi.LocalFileStream.SetLength(0);
}
else if (fdi.DownloadedBytes == 0)
{
fdi.LocalFileStream = File.Create(localfile);
}
dataSocket.ReceiveBufferSize = 1 * 1024 * 1024;
SendCommand("RETR " + fdi.RemoteFileName);
// 等待服务器响应 125 Data connection already open 或 150 about to open data connection
bool response226Ahead = false; // 是否与125,150一同收到了226消息
var msgs = ReceiveResponse(125, 150, 226);
if (msgs == null)
{
throw new FTPResponseException("远程主机对于 RETR 命令没有预期的响应或超时");
}
byte[] buf = new byte[1 * 1024 * 1024];
while (dataSocket.Available > 0 || fdi.DownloadedBytes < fdi.SavedSize)
{
token.ThrowIfCancellationRequested();
var length = dataSocket.Receive(buf);
if (dataSocket.Connected == false)
{
throw new FTPResponseException("远程主机断开连接");
}
fdi.LocalFileStream.Write(buf, 0, length);
fdi.DownloadedBytes += length;
}
if (!response226Ahead)
{
WaitResponse(226);
}
dataSocket.Shutdown(SocketShutdown.Send);
fdi.LocalFileStream.Close();
dataSocket.Disconnect(true);
if (fdi.DownloadedBytes != remote_size)
{
throw new FTPResponseException("下载的字节数与远程文件大小不一致 " + localfile);
}
}
catch (OperationCanceledException)
{
throw;
}
catch (Exception ex)
{
throw new FTPResponseException(ex.Message);
}
}