(Delphi ActiveX) Unzip an AES Encrypted Text File directly into a String Variable

A common need is to unzip from an AES encrypted Zip archive directly into a string variable, such that the unencrypted file never resides on disk, even temporarily. This example shows how to do it.

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
zip: TChilkatZip;
success: Integer;
entry: IChilkatZipEntry;
lineEndingBehavior: Integer;
srcCharset: WideString;
xmlText: WideString;

begin
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

zip := TChilkatZip.Create(Self);

// This example opens a WinZip-compatible AES encrypted
// .zip that contains a single file: hamlet.xml.

// It decrypts and unzips hamlet.xml directly into a string
// variable.
zip.SetPassword('secret');
success := zip.OpenZip('qa_data/hamlet.zip');
if (success <> 1) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

entry := zip.GetEntryByName('hamlet.xml');
if (zip.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add('Failed to find entry in zip');
    Exit;
  end;

// lineEndingBehavior:
// 0 = leave unchanged.
// 1 = convert all to bare LF's
// 2 = convert all to CRLF's
lineEndingBehavior := 0;
srcCharset := 'utf-8';
xmlText := entry.UnzipToString(lineEndingBehavior,srcCharset);
Memo1.Lines.Add(xmlText);
end;