程序的实现步骤 2.2 添加类 CLine class CLine: public Cobject p CPoint m_pt Start CPoint m ptEnd CLine CLine(CPoint pt1, CPoint pt2) virtual -CLine 0 void DraW(CDC*pDC)程序的实现步骤 1. 添加类CLine 2.2 class CLine : public CObject { public: CPoint m_ptStart; CPoint m_ptEnd; CLine(); CLine(CPoint pt1, CPoint pt2); virtual ~CLine(); void Draw(CDC *pDC); };