(Delphi ActiveX) Find a ZIP Entry by EntryID Using EntryById

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This example demonstrates how to use the EntryById method to retrieve a ZIP entry using its unique EntryID.

Each ZipEntry object has an EntryID property that uniquely identifies the entry within the currently open ZIP object.

This is useful when:

• An application stores EntryID values for later use
• ZIP entries need to be retrieved without searching by filename
• Multiple entries may have similar names or paths

The example:

• Opens a ZIP archive
• Retrieves an entry using EntryAt
• Saves the entry's EntryID
• Uses EntryById to retrieve the same entry later

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;
entryId: Integer;
entry2: TChilkatZipEntry;

begin
success := 0;

success := 0;

// Open an existing ZIP archive.
zip := TChilkatZip.Create(Self);

success := zip.OpenZip('example.zip');
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

// Retrieve the first entry in the ZIP archive.
entry := TChilkatZipEntry.Create(Self);

success := zip.EntryAt(0,entry.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Original entry:');
Memo1.Lines.Add('  FileName: ' + entry.FileName);
Memo1.Lines.Add('  EntryID: ' + IntToStr(entry.EntryID));
Memo1.Lines.Add('');

// Save the EntryID for later use.
entryId := entry.EntryID;

// Create another ZipEntry object.
entry2 := TChilkatZipEntry.Create(Self);

// Retrieve the same entry using EntryById.
success := zip.EntryById(entryId,entry2.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(zip.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Entry retrieved by EntryID:');
Memo1.Lines.Add('  FileName: ' + entry2.FileName);
Memo1.Lines.Add('  EntryID: ' + IntToStr(entry2.EntryID));
Memo1.Lines.Add('');

// The filenames and EntryID values should match.
zip.CloseZip();

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