(Delphi ActiveX) Get Compressed ZIP Entry Data as Base64 Using ZipEntry.CopyToBase64

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This example creates a small ZIP archive containing a text file added from memory, writes the ZIP to disk, re-opens it, and then uses ZipEntry.CopyToBase64 to retrieve the compressed data for the text file as a Base64-encoded string.

The Base64 string returned by CopyToBase64 represents the compressed bytes stored for the entry inside the ZIP archive. It is not the original uncompressed text data.

Note: This example requires Chilkat v11.0.0 or greater.

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
success: Integer;
zip: TChilkatZip;
zip2: TChilkatZip;
entry: TChilkatZipEntry;
b64: WideString;

begin
success := 0;

// ------------------------------------------------------------
// First create a sample ZIP archive containing a small text file.

zip := TChilkatZip.Create(Self);

success := zip.NewZip('c:/temp/sampleText.zip');
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

// Add a small text file from memory.
// The text is stored in the ZIP as "hello.txt".
success := zip.AddString('hello.txt','Hello from a ZIP entry!','utf-8');
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

// Write the ZIP archive to disk and close it.
success := zip.WriteZipAndClose();
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

// ------------------------------------------------------------
// Now open the ZIP archive we just created.

zip2 := TChilkatZip.Create(Self);

success := zip2.OpenZip('c:/temp/sampleText.zip');
if (success = 0) then
  begin
    Memo1.Lines.Add(zip2.LastErrorText);
    Exit;
  end;

// Get the text file entry.
entry := TChilkatZipEntry.Create(Self);

success := zip2.EntryOf('hello.txt',entry.ControlInterface);

if (success = 0) then
  begin
    Memo1.Lines.Add('Entry not found.');
    Exit;
  end;

// Get the compressed ZIP entry data as Base64.
// 
// This is the compressed data stored inside the ZIP file,
// not the uncompressed text "Hello from a ZIP entry!".
b64 := entry.CopyToBase64();

Memo1.Lines.Add('Base64 compressed ZIP entry data:');
Memo1.Lines.Add(b64);

zip2.CloseZip();

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