Sample code for 30+ languages & platforms
Delphi ActiveX

Replace/Update a FIle in a .zip

See more Zip Examples

Demonstrates how to replace/update a file from a .zip. Note: This requires the entire .zip to be rewritten.

Chilkat Delphi ActiveX Downloads

Delphi ActiveX
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
success: Integer;
zip: TChilkatZip;
charset: WideString;
zip2: TChilkatZip;
entry: TChilkatZipEntry;

begin
success := 0;

// This requires the Chilkat Zip API to have been previously unlocked.
// See Unlock Chilkat Zip for sample code.

// First prepare a .zip and write it..
zip := TChilkatZip.Create(Self);

zip.NewZip('qa_output/abc.zip');

// Add some files..
charset := 'utf-8';
zip.AddString('a.txt','aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',charset);
zip.AddString('b.txt','bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb',charset);
zip.AddString('c.txt','cccccccccccccccccccccccccccccccccccc',charset);

// Write to qa_output/abc.zip
// This .zip contains three files: a.txt, b.txt, and c.txt
success := zip.WriteZipAndClose();

// -------------------------------------------------------------------
// Open abc.zip, replace the content of the "b.txt" entry with something else, and re-write.
zip2 := TChilkatZip.Create(Self);
zip2.OpenZip('qa_output/abc.zip');

entry := TChilkatZipEntry.Create(Self);
if (zip2.EntryOf('b.txt',entry.ControlInterface) = 1) then
  begin
    entry.ReplaceString('This is the new content.  bbbbbbbbbbbbbbbbbbbbbb','utf-8');
  end;

// Write the modified .zip back to "abc.zip"
success := zip2.WriteZipAndClose();

Memo1.Lines.Add('success.');
end;