直接监听onKeyDown方法

1.   @Override
2.   public boolean onKeyDown(int keyCode, KeyEvent event) {
3.   if (KeyEvent.KEYCODE_HEADSETHOOK == keyCode) { //按下了耳机键
4.   if (event.getRepeatCount() == 0) { //如果长按的话，getRepeatCount值会一直变大
5.   //短按
6.   } else {
7.   //长按
8.   }
9.   }
10.   }

11.