protected override void Dispose(bool disposing)
        {
            base.Dispose(disposing);
            if (disposing)
            {
                if (_controlBoxManager != null)
                {
                    _controlBoxManager.Dispose();
                    _controlBoxManager = null;
                }

                _renderer = null;
                _toolTip.Dispose();
            }
        }
 protected override void OnMouseLeave(EventArgs e)
 {
     base.OnMouseLeave(e);
     ControlBoxManager.ProcessMouseOperate(
         Point.Empty, MouseOperate.Leave);
 }
 protected override void OnMouseHover(EventArgs e)
 {
     base.OnMouseHover(e);
     ControlBoxManager.ProcessMouseOperate(
         PointToClient(MousePosition), MouseOperate.Hover);
 }
 protected override void OnMouseUp(MouseEventArgs e)
 {
     base.OnMouseUp(e);
     ControlBoxManager.ProcessMouseOperate(
         e.Location, MouseOperate.Up);
 }