procedure TForm1.ImageEnView1LayerNotify(Sender: TObject; layer: integer;
event: TIELayerEvent);
{ ImageEnView layer notify. }
begin
  if event = ielSelected then
  begin
    { Show the current layer number }
    ShowMessage('The current layer is ' + IntToStr(layer) + '.');
  end;
end;

procedure TForm1.ImageEnView1Click(Sender: TObject);
var
  i: integer;
begin
  { Show the current layer number }
  i := ImageEnView1.LayersCurrent;
  ShowMessage('The current layer is ' + IntToStr(i) + '.');
end;