protected virtual void TrackBarDrawVerticalThumb (Graphics dc, Rectangle thumb_pos, Brush br_thumb, Rectangle clippingArea, TrackBar trackBar)
{
Pen pen = SystemPens.ControlLightLight;
dc.DrawLine (pen, thumb_pos.X, thumb_pos.Y, thumb_pos.X, thumb_pos.Y + 9);
dc.DrawLine (pen, thumb_pos.X, thumb_pos.Y, thumb_pos.X + 19, thumb_pos.Y);
pen = SystemPens.ControlDark;
dc.DrawLine (pen, thumb_pos.X + 1, thumb_pos.Y + 9, thumb_pos.X + 19, thumb_pos.Y + 9);
dc.DrawLine (pen, thumb_pos.X + 10, thumb_pos.Y + 1, thumb_pos.X + 19, thumb_pos.Y + 8);
pen = SystemPens.ControlDarkDark;
dc.DrawLine (pen, thumb_pos.X, thumb_pos.Y + 10, thumb_pos.X + 20, thumb_pos.Y + 10);
dc.DrawLine (pen, thumb_pos.X + 20, thumb_pos.Y, thumb_pos.X + 20, thumb_pos.Y + 9);
dc.FillRectangle (br_thumb, thumb_pos.X + 1, thumb_pos.Y + 1, 18, 8);
}
#endregion
