说明：  自做的一个流程流码,用于判断C51单片机的长按与短按键的功能(一键多功能),自动调用相应的处理函数.修改下还可以实现更多的功能.
(Since the flow stream to do a code, used to judge the long-C51 single-chip microcomputer according to the function keys and a short (one multi-function keys), automatically call the corresponding handler. Modification can be achieved under more.)