Delphi DLL

Merge ZIP Archives Using AppendZip

See more Zip Examples

This example demonstrates how to use the AppendZip method to append all entries from one ZIP archive into another ZIP archive.

The AppendZip method reads the entries from an existing ZIP file in the local filesystem and appends them to the current in-memory Zip object.

This is useful for:

• Merging multiple ZIP archives into a single ZIP
• Adding the contents of a previously created ZIP archive
• Building larger ZIP archives from smaller ZIP files

The appended entries are not written to the output ZIP until a Write* method is called.

Suppose the ZIP archive reports.zip contains:

reports/january.pdf
reports/february.pdf

And suppose the ZIP archive images.zip contains:

images/logo.png
images/banner.jpg

After calling AppendZip for both ZIP files and writing the final ZIP archive, the resulting ZIP will contain:

reports/january.pdf
reports/february.pdf
images/logo.png
images/banner.jpg

te> Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
zip: HCkZip;

begin
success := False;

// --------------------------------------------------------------------------------
// Note: The AppendZip method is currently not working and will be fixed in v11.5.0
// --------------------------------------------------------------------------------
zip := CkZip_Create();

success := CkZip_NewZip(zip,'merged.zip');
if (success = False) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;

// Append all entries from reports.zip.
success := CkZip_AppendZip(zip,'c:/zips/reports.zip');
if (success = False) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;

// Append all entries from images.zip.
success := CkZip_AppendZip(zip,'c:/zips/images.zip');
if (success = False) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;

// Additional entries can still be added.
success := CkZip_AddString(zip,'readme.txt','Merged ZIP archive','utf-8');
if (success = False) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;

// Write the final ZIP archive.
success := CkZip_WriteZipAndClose(zip);
if (success = False) then
  begin
    Memo1.Lines.Add(CkZip__lastErrorText(zip));
    Exit;
  end;

Memo1.Lines.Add('ZIP archive created successfully.');

CkZip_Dispose(zip);

end;