void CDocView View: OnLButtonUp UINT nFlags, CPoint point) if( m bOuse Down m bOuse Down false: ReleaseCaptureo Clip Cursor( NULL ) CClientDC dc(this) dc. SetROP2( R2 NOT); dc. Move To( m_ ptstart ) dc Line To( m_told) dc. SetROP2( R2 COPYPEN ) dc. Move To( m_ ptstart ) dc Line To( point ) CDocView Doc *pDoc= GetDocumento: ∥得到文档类指针 CLine' pLine= new cLine( m ptstart, point);∥创建 CLine对象 pDc> m linelist. Add tail((oid) pLine);∥将 pLine加入到链表中 Setcursor( m harrow;∥i设置鼠标形状为标准箭头形 CView. OnLButtonUp(nFlags, point程序的实现步骤 2.2 void CDocViewView::OnLButtonUp(UINT nFlags, CPoint point) { if( m_bMouseDown ) { m_bMouseDown = false; ReleaseCapture(); ClipCursor( NULL ); CClientDC dc(this); dc.SetROP2( R2_NOT ); dc.MoveTo( m_ptStart ); dc.LineTo( m_ptOld ); dc.SetROP2( R2_COPYPEN ); dc.MoveTo( m_ptStart ); dc.LineTo( point ); CDocViewDoc *pDoc = GetDocument(); //得到文档类指针 CLine *pLine = new CLine(m_ptStart,point); //创建CLine对象 pDoc->m_LineList.AddTail( (void *) pLine); //将pLine加入到链表中 } SetCursor(m_hArrow); //设置鼠标形状为标准箭头形 CView::OnLButtonUp(nFlags, point); }