Lazarus Pascal Requires Chilkat v11.0.0+

Find a ZIP Entry by EntryID Using EntryById

See more Zip Examples

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

Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.ZipEntry,
  Chilkat.Zip;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  zip: TZip;
  entry: TZipEntry;
  entryId: Integer;
  entry2: TZipEntry;

begin
  success := False;

  //  Open an existing ZIP archive.
  zip := TZip.Create;

  success := zip.OpenZip('example.zip');
  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  //  Retrieve the first entry in the ZIP archive.
  entry := TZipEntry.Create;

  success := zip.EntryAt(0,entry);
  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  WriteLn('Original entry:');
  WriteLn('  FileName: ' + entry.FileName);
  WriteLn('  EntryID: ' + entry.EntryID);
  WriteLn('');

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

  //  Create another ZipEntry object.
  entry2 := TZipEntry.Create;

  //  Retrieve the same entry using EntryById.
  success := zip.EntryById(entryId,entry2);
  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  WriteLn('Entry retrieved by EntryID:');
  WriteLn('  FileName: ' + entry2.FileName);
  WriteLn('  EntryID: ' + entry2.EntryID);
  WriteLn('');

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

  WriteLn('Done.');


  zip.Free;
  entry.Free;
  entry2.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.