Delphi ActiveX

Download an FTP File to a Stream

Demonstrates the Chilkat Ftp2.GetFileToStream method, which downloads a remote file and writes its bytes to a Stream. The first argument is the remote file path and the second is the Stream, which must have a destination sink configured beforehand.

Note: The local paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: Streaming to a Stream object decouples the download from where the bytes ultimately go — a file (as here, via SinkFile), or a pipe feeding another component such as a decompressor or a hashing routine — and processes the data as it arrives rather than buffering the whole file. That keeps memory flat for large downloads and lets you chain the transfer into a processing pipeline.

Chilkat Delphi ActiveX Downloads

Download Chilkat for Delphi ActiveX

Delphi ActiveX

var
success: Integer;
ftp: TChilkatFtp2;
fileStream: TChilkatStream;

begin
success := 0;

//  Demonstrates the Ftp2.GetFileToStream method, which downloads a remote file and writes its
//  bytes to a Stream.  The 1st argument is the remote file path and the 2nd is the Stream.

ftp := TChilkatFtp2.Create(Self);

ftp.Hostname := 'ftp.example.com';
ftp.Username := 'myFtpLogin';

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
ftp.Password := 'myPassword';

success := ftp.Connect();
if (success = 0) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;

//  Configure the stream's destination sink before downloading.  Here the stream writes to a
//  local file.
fileStream := TChilkatStream.Create(Self);
fileStream.SinkFile := 'qa_output/report.pdf';

success := ftp.GetFileToStream('public_html/report.pdf',fileStream.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('Downloaded to stream.');

success := ftp.Disconnect();
if (success = 0) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;