Как использовать свойство Objects в TStringGrid?

procedure TForm1.Button1Click(Sender: TObject);
var
  i : Integer;
  pb : TProgressBar;
begin
  StringGrid1.Options := StringGrid1.Options - [goSmoothScroll];
  for i := 1 to StringGrid1.RowCount - 1 do
  begin
    StringGrid1.Cells[1, i] := 'Row ' + IntToStr(i);
    pb := TProgressBar.Create(StringGrid1);
    pb.Parent := StringGrid1;
    pb.Visible := False;
 
 
    StringGrid1.Cells[StringGrid1.ColCount - 1, i] :=
      IntToStr(Random(90) + 10);
    StringGrid1.Objects[StringGrid1.ColCount - 1, i] := (pb as TObject);
  end;
  StringGrid1.OnDrawCell := @StringGrid1DrawCell;
 
end;
 
procedure TForm1.FormCreate(Sender: TObject);
begin
  StringGrid1.OnDrawCell := nil;
end;
 
procedure TForm1.StringGrid1DrawCell(Sender: TObject; aCol, aRow: Integer;
  aRect: TRect; aState: TGridDrawState);
var
  Grid : TStringGrid;
  pb : TProgressBar;
  R : TRect;
begin
  Grid := Sender as TStringGrid;
 
  if Assigned(Grid.Objects[ACol, ARow]) then
  begin
    R := ARect;
    R.Inflate(-1, -1);
    pb := Grid.Objects[ACol, ARow] as TProgressBar;
    pb.BoundsRect := R;
    pb.Visible := True;
    pb.Position := StrToInt(Grid.Cells[ACol, ARow]);
  end;
end;

StringGrid1.Cells[StringGrid1.ColCount - 1, i] := IntToStr(Random(90) + 10);
    StringGrid1.Objects[StringGrid1.ColCount - 1, i] := (pb as TObject);