https://blog.csdn.net/u012719256/article/details/52252647
https://blog.csdn.net/ifangler/article/details/41248425
https://www.cnblogs.com/windwithlife/archive/2009/07/23/1529680.html
android onKeyDown
原文：https://www.cnblogs.com/pengmn/p/9136594.html
