孙鑫VC学习（第4课--画图）

孙鑫第4课—画图

新建一个MFC的单文档程序。

为VIEW类添加：

private:

       CPoint m_ptOld;

       BOOL m_bDraw;

       CPoint m_ptOrigin;

CDrawView::CDrawView()

{

       // TODO: add construction code here

       m_ptOrigin=0;

       m_ptOld=0;

       m_bDraw=FALSE;

}

void CDrawView::OnLButtonDown(UINT nFlags, CPoint point)

{

       // TODO: Add your message handler code here and/or call default

       m_ptOrigin=m_ptOld=point;

       m_bDraw=TRUE;

       CView::OnLButtonDown(nFlags, point);

}

void CDrawView::OnLButtonUp(UINT nFlags, CPoint point)

{

       // TODO: Add your message handler code here and/or call default

       m_bDraw=FALSE;

       CView::OnLButtonUp(nFlags, point);

}

void CDrawView::OnMouseMove(UINT nFlags, CPoint point)

{

       // TODO: Add your message handler code here and/or call default

       CClientDC dc(this);

       CPen pen(PS_SOLID,1,RGB(255,0,0));

       CPen *pOldPen=dc.SelectObject(&pen);

       if(m_bDraw==TRUE)

       {

              dc.SetROP2(R2_BLACK);

              dc.MoveTo(m_ptOrigin);

              //dc.LineTo(point);

              dc.LineTo(m_ptOld);

              //dc.MoveTo(m_ptOrigin);

              dc.MoveTo(m_ptOld);

              dc.LineTo(point);

              //m_ptOrigin=point;

              m_ptOld=point;

       }

       dc.SelectObject(pOldPen);

       CView::OnMouseMove(nFlags, point);

}