实现菜单式功能,主要体现在用少数几个按键可以调用多种界面,以及多个程序入口,其中其中KeyTab的设计颇费尽心机,值得借鉴-realization of menu-function primarily reflected in the use of a few keys can call multiple interface and the entrance of a number of procedures, which KeyTab quite a lot of the design, which is worth learning from