procedure TForm1.ListBox1DrawItem(Control: TWinControl; index: integer; Rect: TRect;
                                  State: TOwnerDrawState);
var
  ListColor: TColor;
  ListBrush: TBrush;
begin { TForm1.ListBox1DrawItem }

  // create a brush to paint the item's background
  ListBrush := TBrush.Create;

  // get a canvas to draw - this is a canvas for the complete listbox!
  with (Control as TListBox).Canvas do
  begin
    // put out lines in alternating colors
    if not Odd(index) then
      ListColor := clSilver;
    else
      ListColor := clWhite;

    ListBrush.Style := bsSolid;
    ListBrush.Color := ListColor;
    Windows.FillRect(Handle, Rect, ListBrush.Handle);
    Brush.Style := bsClear;

    // write out the text
    TextOut(Rect.Left, Rect.Top, (Control as TListBox).Items[index]);

    ListBrush.Free
  end; { with (Control as TListBox).Canvas }
end; { TForm1.ListBox1DrawItem }