void CMy1_1View::OnMouseMove(UINT nFlags, CPoint point) 
{
CClientDC dc(this);
CBrush *brush=CBrush::FromHandle((HBRUSH)GetStockObject(NULL_BRUSH));
CBrush *poldBrush=dc.SelectObject(brush);
CPen pen(0,0,RGB(0,0,0));
CPen* poldpen=dc.SelectObject(&pen);

if(m_draw==1)
{ dc.SetROP2(R2_NOT);
// dc.TextOut(oldpoint.x+10,oldpoint.y+10,"zhangpeng");
dc.Rectangle(oldpoint.x,oldpoint.y,oldpoint.x+100,oldpoint.y+100);
m_draw=0;
}


if(m_draw==0)
{
dc.SetROP2(R2_NOT);
dc.Rectangle(point.x,point.y,point.x+100,oldpoint.y+100);
// dc.TextOut(point.x+10,point.y+10,"zhangpeng");
m_draw=1;
oldpoint=point;
}


dc.SelectObject(poldpen);

dc.SelectObject(poldBrush);
}
上面是我的做法,但是实现的结果,和预期的有很大出路。