再按一次退出——两种方式实现

来源：互联网发布：负离子吹风机知乎编辑：程序博客网时间：2024/06/05 11:09

方式一：

private boolean isExit = false;private Handler mHandler = new Handler() {    @Override    public void handleMessage(Message msg) {        switch (msg.what) {            case 0:                isExit = false;                break;        }    }};@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {    if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {        if (isExit) {            mHandler.removeCallbacksAndMessages(null);        } else {            isExit = true;            mHandler.sendEmptyMessageDelayed(0, 3000);            Toast.makeText(MainActivity.this, "再按一次退出", Toast.LENGTH_SHORT).show();            return true;        }    }    return super.onKeyDown(keyCode, event);}

方式二：

private long exitTime = 0;@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {    if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {        if (System.currentTimeMillis() - exitTime > 3000) {            Toast.makeText(getApplicationContext(), "再按一次返回键退出", Toast.LENGTH_SHORT).show();            exitTime = System.currentTimeMillis();        } else {            finish();        }        return true;    }    return super.onKeyDown(keyCode, event);}

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