说明：  按键处理，可以说，是做单片机的朋友的一项必须掌握的基本功。在本文中，匠人将试 对按键的检测及处理做一些肤浅的分析，权当是给新手扫盲。如果您是高手，请跳过此文，
(Button processing, it can be said, is to do a friend of a microcontroller must master the basics. In this article, and craftsmen, on the button will try to do some testing and treatment of superficial analysis, the weighting is to give novice when literacy. If you are an expert, please skip this article,)