(Delphi ActiveX) Restart/Resume FTP Upload

Demonstrates how to restart / resume an FTP upload.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

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

begin
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

ftp := TChilkatFtp2.Create(Self);

ftp.Hostname := 'ftp.example.com';
ftp.Username := 'login';
ftp.Password := 'password';

// Connect and login to the FTP server.
success := ftp.Connect();
if (success <> 1) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;

// Change to the remote directory where the file will be uploaded.
success := ftp.ChangeRemoteDir('temp');
if (success <> 1) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;

// In this example, assume that a previous FTP upload failed,
// and the incomplete file (bigFile.zip) exists on the FTP server.
// You only need to set the RestartNext property to resume
// the upload.  When RestartNext is set, the next call
// to PutFile (or PutFileFromBinaryData, PutFileFromTextData)
// will automatically resume the upload from the point of failure.
// (The way it works is that the FTP component sends a "SIZE"
// command to the FTP server to find out how many bytes of
// the file already exist on the server.  It then begins
// uploading from that point.

// Note: After PutFile is called, the RestartNext property
// is automatically set to false.
ftp.RestartNext := 1;

// Upload a file with restart.
localFilename := 'bigFile.zip';
remoteFilename := 'bigFile.zip';

success := ftp.PutFile(localFilename,remoteFilename);
if (success <> 1) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;

success := ftp.Disconnect();

Memo1.Lines.Add('File Uploaded!');
end;