这样简单的问题都搞不定1

type
  TFake = class (TDBGrid);procedure TForm1.DBGrid1ColEnter(Sender: TObject);
begin
  Label1.Caption := Format (
    'Column: %2d; Row: %2d',
    [TFake (DbGrid1).Col,     //若把TFake换成DBGrid，便出错，找不到Col
    TFake (DbGrid1).Row]);
end;请问这是怎么回事，Col,在TFake类中又有吗？？？