正确进行线程化FTP下载(Indy/Android)
我已经做了一个IdFTP从我的FTP服务器下载文件,但是当我试图使它线程化时,它在解析主机名时卡住了。。。在Android操作系统中 无螺纹工作良好:正确进行线程化FTP下载(Indy/Android),android,delphi,ftp,indy,delphi-10.1-berlin,Android,Delphi,Ftp,Indy,Delphi 10.1 Berlin,我已经做了一个IdFTP从我的FTP服务器下载文件,但是当我试图使它线程化时,它在解析主机名时卡住了。。。在Android操作系统中 无螺纹工作良好: uses ..., IdFTPCommon; var RecordDownload: TMemoryStream; uses System.IOUtils; procedure TForm1.Button1Click(Sender: TObject); begin IdFTP1.Host := 'motoristaajudante.
uses ..., IdFTPCommon;
var
RecordDownload: TMemoryStream;
uses System.IOUtils;
procedure TForm1.Button1Click(Sender: TObject);
begin
IdFTP1.Host := 'motoristaajudante.ddns.net';
IdFTP1.Port := 2121;
IdFTP1.DataPortMin := 50100;
IdFTP1.DataPortMax := 51100;
IdFTP1.Username := 'anonymous';
IdFTP1.TransferType := IdFTPCommon.TIdFTPTransferType.ftBinary;
IdFTP1.Passive := True;
try
IdFTP1.Connect();
IdFTP1.Get('00001.m4a',TPath.GetDocumentsPath + PathDelim + '00001.m4a',True,False);
except
IdFTP1.Disconnect;
end;
end;
procedure TForm1.IdFTP1AfterGet(ASender: TObject; AStream: TStream);
begin
IdFTP1.Disconnect;
end;
procedure TForm1.IdFTP1WorkEnd(ASender: TObject; AWorkMode: TWorkMode);
begin
if FileExists(TPath.GetDocumentsPath + PathDelim + '00001.m4a') then
begin
ShowMessage('Downloaded!');
end;
end;
我编写的线程代码如下:
然后FTP状态显示它在解析主机名时卡住了。。。。如何使其正确线程化?没有理由像使用OnAfterGet和OnWorkEnd事件那样使用它们。印地是同步的。在传输完成之前,TIdFTP.Get不会返回,如果发生错误,则会引发异常 因此,去掉这两个事件处理程序,使用try/finally而不是try/except来调用Disconnect,并且仅当get没有引发时才处理下载 OnWorkEnd和OnStatus事件在调用Connect、Disconnect和Get的同一线程的上下文中触发。因此,在线程示例中,这将是工作线程,而不是主线程。但是,事件处理程序没有同步对UI控件的访问。这可能会导致各种问题,包括您正在经历的冻结。您必须同步TThread.OnTerminated事件 话虽如此,请尝试以下方法: 非线程:
uses
..., IdFTPCommon;
...
procedure TForm1.Button1Click(Sender: TObject);
begin
IdFTP1.Host := 'motoristaajudante.ddns.net';
IdFTP1.Port := 2121;
IdFTP1.DataPortMin := 50100;
IdFTP1.DataPortMax := 51100;
IdFTP1.Username := 'anonymous';
IdFTP1.TransferType := IdFTPCommon.TIdFTPTransferType.ftBinary;
IdFTP1.Passive := True;
try
IdFTP1.Connect;
try
IdFTP1.Get('00001.m4a', TPath.GetDocumentsPath + PathDelim + '00001.m4a', True, False);
finally
IdFTP1.Disconnect;
end;
ShowMessage('Downloaded!');
except
ShowMessage('Error while downloading!');
end;
end;
螺纹:
uses
..., IdFTPCommon;
type
TLoadThread = class(TThread)
public
constructor Create; reintroduce;
protected
procedure Execute; override;
end;
type
TForm1 = class(TForm)
...
IdFTP1: TIdFTP;
procedure ThreadTerminated(Sender: TObject);
...
private
Loading: Boolean;
zLThread: TLoadThread;
end;
...
constructor TLoadThread.Create;
begin
inherited Create(True);
FreeOnTerminate := True;
end;
procedure TLoadThread.Execute;
begin
Form1.IdFTP1.Connect;
try
Form1.IdFTP1.Get('00001.m4a', TPath.GetDocumentsPath + PathDelim + '00001.m4a', True, False);
finally
Form1.IdFTP1.Disconnect;
end;
end;
procedure TForm1.ThreadTerminated(Sender: TObject);
begin
zLThread := nil;
Loading := False;
FloatAnimation1.Enabled := False;
FloatAnimation2.Enabled := False;
Arc3.StartAngle := -90;
Arc3.EndAngle := 0;
If TThread(Sender).FatalException = nil then
ShowMessage('Downloaded!')
else
ShowMessage('Error while Downloading!');
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
IdFTP1.Host := 'motoristaajudante.ddns.net';
IdFTP1.Port := 2121;
IdFTP1.DataPortMin := 50100;
IdFTP1.DataPortMax := 51100;
IdFTP1.Username := 'anonymous';
IdFTP1.TransferType := IdFTPCommon.TIdFTPTransferType.ftBinary;
IdFTP1.Passive := True;
zLThread := TLoadThread.Create;
zLThread.OnTerminate := ThreadTerminated;
zLThread.Start;
Loading := True;
FloatAnimation1.Enabled := True;
FloatAnimation2.Enabled := True;
end;
procedure TForm1.IdFTP1Status(ASender: TObject; const AStatus: TIdStatus; const AStatusText: string);
begin
TThread.Queue(nil,
procedure
begin
Memo1.Lines.Add(AStatusText);
end
);
end;
没有理由按照您使用OnAfterGet和OnWorkEnd事件的方式使用它们。印地是同步的。在传输完成之前,TIdFTP.Get不会返回,如果发生错误,则会引发异常 因此,去掉这两个事件处理程序,使用try/finally而不是try/except来调用Disconnect,并且仅当get没有引发时才处理下载 OnWorkEnd和OnStatus事件在调用Connect、Disconnect和Get的同一线程的上下文中触发。因此,在线程示例中,这将是工作线程,而不是主线程。但是,事件处理程序没有同步对UI控件的访问。这可能会导致各种问题,包括您正在经历的冻结。您必须同步TThread.OnTerminated事件 话虽如此,请尝试以下方法: 非线程:
uses
..., IdFTPCommon;
...
procedure TForm1.Button1Click(Sender: TObject);
begin
IdFTP1.Host := 'motoristaajudante.ddns.net';
IdFTP1.Port := 2121;
IdFTP1.DataPortMin := 50100;
IdFTP1.DataPortMax := 51100;
IdFTP1.Username := 'anonymous';
IdFTP1.TransferType := IdFTPCommon.TIdFTPTransferType.ftBinary;
IdFTP1.Passive := True;
try
IdFTP1.Connect;
try
IdFTP1.Get('00001.m4a', TPath.GetDocumentsPath + PathDelim + '00001.m4a', True, False);
finally
IdFTP1.Disconnect;
end;
ShowMessage('Downloaded!');
except
ShowMessage('Error while downloading!');
end;
end;
螺纹:
uses
..., IdFTPCommon;
type
TLoadThread = class(TThread)
public
constructor Create; reintroduce;
protected
procedure Execute; override;
end;
type
TForm1 = class(TForm)
...
IdFTP1: TIdFTP;
procedure ThreadTerminated(Sender: TObject);
...
private
Loading: Boolean;
zLThread: TLoadThread;
end;
...
constructor TLoadThread.Create;
begin
inherited Create(True);
FreeOnTerminate := True;
end;
procedure TLoadThread.Execute;
begin
Form1.IdFTP1.Connect;
try
Form1.IdFTP1.Get('00001.m4a', TPath.GetDocumentsPath + PathDelim + '00001.m4a', True, False);
finally
Form1.IdFTP1.Disconnect;
end;
end;
procedure TForm1.ThreadTerminated(Sender: TObject);
begin
zLThread := nil;
Loading := False;
FloatAnimation1.Enabled := False;
FloatAnimation2.Enabled := False;
Arc3.StartAngle := -90;
Arc3.EndAngle := 0;
If TThread(Sender).FatalException = nil then
ShowMessage('Downloaded!')
else
ShowMessage('Error while Downloading!');
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
IdFTP1.Host := 'motoristaajudante.ddns.net';
IdFTP1.Port := 2121;
IdFTP1.DataPortMin := 50100;
IdFTP1.DataPortMax := 51100;
IdFTP1.Username := 'anonymous';
IdFTP1.TransferType := IdFTPCommon.TIdFTPTransferType.ftBinary;
IdFTP1.Passive := True;
zLThread := TLoadThread.Create;
zLThread.OnTerminate := ThreadTerminated;
zLThread.Start;
Loading := True;
FloatAnimation1.Enabled := True;
FloatAnimation2.Enabled := True;
end;
procedure TForm1.IdFTP1Status(ASender: TObject; const AStatus: TIdStatus; const AStatusText: string);
begin
TThread.Queue(nil,
procedure
begin
Memo1.Lines.Add(AStatusText);
end
);
end;
谢谢你,雷米,它工作得很好,给我一个处理下载错误的方法。谢谢你,雷米,它工作得很好,给我一个处理下载错误的方法。