error in dbgrid painting when using DrawCell event

[tester-dev]

Bonjour. I am using kdbgrid from KControls for lazarus. 1- When i add this :

Code: Pascal  [Select][+][-]

1. procedure TForm1.KDBGrid1DrawCell(Sender: TObject; ACol, ARow: Integer;
2.   R: TRect; State: TKGridDrawState);
3.  
4. begin
5.     if (aCol <> 1) or (aRow = 0) then begin
6.         Exit;
7.     end;
8.       if (aCol=2) and (aRow > 1) then begin
9.         KDBGrid1.CellRect(aCol, ARow,R);
10.         R.Left := R.Right - (R.Bottom - R.Top);
11.         Button3.BoundsRect := R;
12.         KDBGrid1.Editor.Assign(Button3);
13.       end;
14. end

my dbgrid does't show correctly.

so i can't add any buttons to the cells of the grid or images in a permanent way. I read the help (kgrid_manual.pdf) but i didn't find any thin.

thanks a lot .