在程序中添加一个【绘图】菜单项，在该项的子菜单中有【正方形】、【椭圆】、【三角形】、【平行四边形】等菜单选项。选中一菜单项会在应用程序窗口的用户区中画出相应的图形，同时清除原有图形。

2、阅读VC++的帮助文档，了解一个名称为StretchBlt的函数，该函数与BitBlt函数一样可以把内存中的位图显示在显示器的屏幕上，但它与BitBlt不同的地方是可以把位图拉伸或缩小。请用这个函数编制一个可以对位图放大或缩小的应用程序。

-In the process of drawing】 【Add a menu item, a submenu in the square have 【】, 【oval】, 【triangle】, 【】 and other menu options parallelogram. Select a menu item in the application window, the user area to draw the corresponding graph, and remove the original graphics. 2, read the VC++ help documentation for a name for StretchBlt function, the function with the BitBlt function is the same as can be in memory bitmap appears in the display screen, but it BitBlt different places that can put a bitmap drawing in or out. Please use this function to prepare a bitmap can zoom in or out of the application.