Is there a TDBComboBox equivalent that goes by Ite

问题:

In the helpfile entry for TDBComboBox, it says that the text of the selected option becomes the new value for the field. Is there any similar control that goes by ItemIndex instead of text? (To represent an enumerated type, for example.)

回答1:

Try the TDBLookupComboBox. Check out the ListField, DataField and KeyField properties.

回答2:

You can fill TDBComboBox items with numbers ('0, '1', '2', ...), but set DBComboBox1.Style to csOwnerDrawFixed and write OnItemDraw event. Something like this:

procedure TForm1.DBComboBox1DrawItem(Control: TWinControl; Index: Integer;
  Rect: TRect; State: TOwnerDrawState);
begin
  with (Sender as TDBComboBox).Canvas do
  begin
    FillRect(Rect);
    TextRect(Rect, Rect.Left+1, Rect.Top+1, MyValueDescriptions[Index]);
  end;
end;