回复 3楼 lxsjzbd
用InvalidateRect(hwnd,NULL,TRUE)把整个客户区变为无效,是啥意思啊?
void CText_3View::OnLButtonDown(UINT nFlags, CPoint point)
{
InvalidateRect(NULL,TRUE);
CClientDC dc(this);
dc.SetROP2(R2_NOT);
dc.Ellipse(point.x,point.y,point.x+10,point.y-10);
CView::OnLButtonDown(nFlags, point);
}错在哪啊,不懂