当wifi打开时如何启动计时器？

WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
BroadcastReceiver wifiStateReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        int wifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN);
        if (wifiState == WifiManager.WIFI_STATE_ENABLED) {
            // Wifi已打开，启动计时器
            startTimer();
        } else if (wifiState == WifiManager.WIFI_STATE_DISABLED) {
            // Wifi已关闭，停止计时器
            stopTimer();
        }
    }
};
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
registerReceiver(wifiStateReceiver, intentFilter);

private CountDownTimer timer;

private void startTimer() {
    timer = new CountDownTimer(60000, 1000) { // 倒计时60秒，每秒触发一次onTick()
        @Override
        public void onTick(long millisUntilFinished) {
            // 每秒触发的操作，可以更新UI显示剩余时间
        }

        @Override
        public void onFinish() {
            // 计时器结束时的操作
        }
    };
    timer.start();
}

private void stopTimer() {
    if (timer != null) {
        timer.cancel();
        timer = null;
    }
}