Delphi - ComboBox en celda de StringGrid

Saludos a todos:
Alguien sabe como meter un ComboBox en una celda de un StringGrid que este se despliegue sin problemas...

Gracias de antemano Efren

type
TForm1 = class(TForm)
StringGrid1: TStringGrid;
ComboBox1: TComboBox;
procedure FormCreate(Sender: TObject);
procedure ComboBox1Change(Sender: TObject);
procedure ComboBox1Exit(Sender: TObject);
procedure StringGrid1SelectCell(Sender: TObject; ACol, ARow: Integer;
var CanSelect: Boolean);
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormCreate(Sender: TObject);
begin
with Combobox1 do
begin
StringGrid1.DefaultRowHeight := Height;
Visible := False;
Items.Add('Item1');
Items.Add('Item2');
Text := 'Select an item';
end;
end;

procedure TForm1.ComboBox1Change(Sender: TObject);
begin
StringGrid1.Cells[StringGrid1.Col, StringGrid1.Row] :=
ComboBox1.Items[ComboBox1.ItemIndex];
ComboBox1.Visible := False;
StringGrid1.SetFocus;
end;

procedure TForm1.ComboBox1Exit(Sender: TObject);
begin
StringGrid1.Cells[StringGrid1.Col, StringGrid1.Row] :=
ComboBox1.Items[ComboBox1.ItemIndex];
ComboBox1.Visible := False;
StringGrid1.SetFocus;
end;

procedure TForm1.StringGrid1SelectCell(Sender: TObject; ACol,
ARow: Integer; var CanSelect: Boolean);
var
R: TRect;
begin
if (ACol = 1) and (ARow <> 0) then
begin
R := StringGrid1.CellRect(ACol, ARow);
R.Left := R.Left + StringGrid1.Left;
R.Right := R.Right + StringGrid1.Left;
R.Top := R.Top + StringGrid1.Top;
R.Bottom := R.Bottom + StringGrid1.Top;
with Combobox1 do
begin
Left := R.Left + 1;
Top := R.Top + 1;
Width := (R.Right + 1) - R.Left;
Height := (R.Bottom + 1) - R.Top;
Visible := True;
SetFocus;
end;
end;
CanSelect := True;
end;