Append Files to Existing Zip w/out Rewriting Entire Zip

Demonstrates how to use the QuickAppend method to append files to an existing .zip archive. This method works by editing the existing .zip -- it does not rewrite or recompress the contents of the existing .zip. It is the fastest way to append additional files to a pre-existing large .zip archive. Note: The QuickAppend method is new and available in the pre-release downloads, or in official releases dated after 6-October-2007.

Download Chilkat Zip ActiveX

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    ChilkatZip2Lib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
zip: TChilkatZip2;
success: Integer;
saveExtraPath: Integer;

begin
zip := TChilkatZip2.Create(Self);

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

  end;

//  The NewZip method only initializes the Zip object -- it does
//  not create or write a .zip file.
success := zip.NewZip('notUsed.zip');
if (success <> 1) then
  begin
    ShowMessage(zip.LastErrorText);

  end;

//  Add a reference to a file.  This is the file that will
//  be added to a pre-existing .zip archive.
//  Note: this does not read or compress the file contents --
//  it simply adds a reference to the zip object.
saveExtraPath := 0;
success := zip.AppendOneFileOrDir('something.dat',saveExtraPath);
if (success <> 1) then
  begin
    ShowMessage(zip.LastErrorText);

  end;

//  Appends the contents of the zip object to the preExisting.zip
//  zip archive.  preExisting.zip is opened, and the files
//  referenced by this zip object are streamed in, compressed,
//  and appended to the end of the archive.
success := zip.QuickAppend('preExisting.zip');
if (success <> 1) then
  begin
    ShowMessage(zip.LastErrorText);

  end;

ShowMessage('Success!');

//  Note: Additional files, directory trees, or in-memory data
//  can be appended by calling AppendOneFileOrDir, AppendFiles,
//  AppendString, AppendData, etc. multiple times.
//  Whatever files and/or in-memory data that are referenced by
//  this zip object will be appended to preExisting.zip when
//  QuickAppend is called.

end;