DBGridEh如何根据不同数值设置单元格不同颜色？

Question

以下方法只把一行的颜色都改变了，而我是要根据单元格的数据值而把相应这一单元格颜色改变，不是整行变。
procedure TMainForm.DBGridEh1DrawColumnCell(Sender: TObject;
  const Rect: TRect; DataCol: Integer; Column: TColumnEh;
  State: TGridDrawState);
  var num:integer;
begin
num:=sx.FieldByName('num').AsInteger;
case num of
1,2,7,8,12:dbgrideh1.Canvas.Brush.Color:=clRed;
5,6,11:dbgrideh1.Canvas.Brush.Color:=clGreen;
3,4,9,10:dbgrideh1.Canvas.Brush.Color:=clBlue;
end;
DBGridEh1.DefaultDrawColumnCell(Rect,DataCol,Column,State);
end;有啥好方法？

Answer 1

procedure TMainForm.DBGridEh1DrawColumnCell(Sender: TObject;
  const Rect: TRect; DataCol: Integer; Column: TColumnEh;
  State: TGridDrawState);
var tmprc: TRect;
  num: Integer;
begin
  if Column.FieldName = 'num' then
  begin
    tmprc := DBGridEh1.CellRect(DataCol+1, 0);
    if tmprc.Left = Rect.Left then
    begin
      num := Column.Field.AsInteger;
      case num of
        1, 2, 7, 8, 12: dbgrideh1.Canvas.Brush.Color := clRed;
        5, 6, 11: dbgrideh1.Canvas.Brush.Color := clGreen;
        3, 4, 9, 10: dbgrideh1.Canvas.Brush.Color := clBlue;
      end;
      DBGridEh1.DefaultDrawColumnCell(Rect, DataCol, Column, State);
    end;
  end;
end;