procedure TForm1.DBComboBox1DrawItem(Control: TWinControl; Index: Integer;
  Rect: TRect; State: TOwnerDrawState);
begin
  with TDBComboBox(Control).Canvas do begin
    if { TODO : 条件 } then begin
      FillRect(Rect);
      Font.Color := clBlue;
      TextOut(Rect.Left, Rect.Top, TDBComboBox(Control).Field.DisplayText);
    end;
  end;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
  DBComboBox1.Style := csOwnerDrawFixed;
end;