单片机C语言下拉式菜单设计,虽是简短，但算法很实用-Design drop-down menu

此程序是模仿了非智能手机的菜单而写的，总共有三层下拉，适合用来搭建比较功能比较多的大型程序框架。以菜单为框架，然后只需要在各级菜单下面添加所需要的功能程序即可。-This procedure is to imitate the non-smart phone' s menu and written down a total of three layers, suitable for building large-scale comparison function are more proc