void CDrawView::OnLButtonUp(UINT nFlags, CPoint point)
{
     CWindowDC dc(GetParent());
     dc.MoveTo(m_ptOrigin);
     dc.LineTo(point);
     CView::OnLButtonUp(nFlags, point);
 }
 划线时咋画不到标题栏上？？？
我看的是孙鑫的视频，为啥在我运行时画不到标题栏上