Asynchronous FTP Upload

The Chilkat FTP component supports asynchronous uploads and downloads. This examples demonstrates doing an upload in a background thread. The upload is started by calling AsyncPutFileStart. While the upload is in progress, your program may do other tasks. You may periodically check the AsyncFinished property to determine when the transfer is finished. The example below provides the remainder of the details.

Download Chilkat FTP2 ActiveX

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATFTP2Lib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
ftp: TChilkatFtp2;
success: Integer;
localFilename: String;
remoteFilename: String;

begin
ftp := TChilkatFtp2.Create(Self);

//  Any string unlocks the component for the 1st 30-days.
success := ftp.UnlockComponent('Anything for 30-day trial');
if (success <> 1) then
  begin
    ShowMessage(ftp.LastErrorText);

  end;

ftp.Hostname := 'ftp.chilkatsoft.com';
ftp.Username := 'mylogin';
ftp.Password := 'mypassword';

//  Connect and login to the FTP server.
success := ftp.Connect();
if (success <> 1) then
  begin
    ShowMessage(ftp.LastErrorText);

  end;

//  Change to the remote directory where the file will be uploaded.
success := ftp.ChangeRemoteDir('junk');
if (success <> 1) then
  begin
    ShowMessage(ftp.LastErrorText);

  end;

localFilename := 'hamlet.xml';
remoteFilename := 'hamlet.xml';

//  Begin the upload in a background thread.
//  Only 1 background upload or download may be active at any time.
//  (per instance of an FTP object)
//  To append to an existing file in the background, call
//  AsyncAppendFileStart instead.
success := ftp.AsyncPutFileStart(localFilename,remoteFilename);
if (success <> 1) then
  begin
    ShowMessage(ftp.LastErrorText);

  end;

//  The application is now free to do anything else
//  while the file is uploading.
//  For this example, we'll simply sleep and periodically
//  check to see if the transfer if finished.  While checking
//  however, we'll report on the progress in both number
//  of bytes tranferred and performance in bytes/second.
while ftp.AsyncFinished <> 1 do
  begin

    Memo1.Lines.Add(IntToStr(ftp.AsyncBytesSent)
         + ' bytes sent');
    Memo1.Lines.Add(IntToStr(ftp.UploadRate)
         + ' bytes per second');

    //  Sleep 1 second.
    ftp.SleepMs(1000);
  end;

//  Did the upload succeed?
if (ftp.AsyncSuccess = 1) then
  begin
    ShowMessage('File Uploaded!');
  end
else
  begin
    //  The error information for asynchronous ops
    //  is in AsyncLog as opposed to LastErrorText
    ShowMessage(ftp.AsyncLog);
  end;

ftp.Disconnect();
end;