这里就不多说了,很容易
//按键返回事件 private long currentBackPressedTime = 0; private static final int BACK_PRESSED_INTERVAL = 2000;
//按键返回事件 public void onBackPressed() { //1.当前的获取的毫秒数-预定值(0)肯定大于2s //4.当下次再按时当前值跟赋予后的设定值比较 if (System.currentTimeMillis() - currentBackPressedTime > BACK_PRESSED_INTERVAL) { //2.把当前的毫秒数赋予预定值 currentBackPressedTime = System.currentTimeMillis(); //3.弹出框 Toast.makeText(Home.this,"再按一次退出", Toast.LENGTH_SHORT).show(); } else { //若当前值-设定值<2s 则执行: finish(); }}