如何让CDC上输出的文字、图形具有保持功能，集合类CPtrArray的使用，CPaintDC与CClientDC的区别与应用，OnPaint与OnDraw在CView中的关系及实现内幕，滚动窗口的实现，坐标空间，映射方式，设备坐标与逻辑坐标的转换。元文件设备描述表的使用，如何利用兼容DC实现图形的保存和再现。-CDC on how to output text, graphics, maintain function, collections CPtrArray use, CPaintDC difference with CClientDC and application, OnPaint and OnDraw in the CView relationships and achieve insider, scrolling window implementation, coordinate space, mapping, device coordinates and logical coordinates conversion. Metafile device context to use, how to use the compatible DC graphics to achieve preservation and reproduction.