学步园

防止重复点击退出按键

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            switch (keyCode) {
                case KEYCODE_BACK:
                    exitDlg(MainActivity.this);
                    return true;
                default:
                    break;
            }
        }
        return super.onKeyDown(keyCode, event);
    }