(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.

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;
entry: TChilkatZipEntry;
lineEndingBehavior: Integer;
srcCharset: WideString;
xmlText: WideString;

begin
success := 0;

// 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 = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

entry := TChilkatZipEntry.Create(Self);
success := zip.EntryOf('hamlet.xml',entry.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    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;