Question

我这样开始Service：

Intent intentService = new Intent(getActivity(), ACNotificationService.class);
intentService.putExtra("ACReservation", reservationActivity.acReservation);
getActivity().startService(intentService);

这是我的Service课程：

/*
Variables
 */

private NotificationManager notificationManager;

private CountDownTimer countDownTimer;

private static int NOTIFICATION_COUNTDOWN = 0;
private static int NOTIFICATION_RANOUT = 1;

private ACReservation acReservation;

/*
Callbacks
 */

@Override
public void onCreate() {
    super.onCreate();

    // Initialize variables
    notificationManager =
            (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);

    // Register EventBus
    EventBus.getDefault().register(this);
}

@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {

    // Get reservation data from extras
    if (acReservation == null) {
        acReservation = (ACReservation) intent.getExtras().get("ACReservation");
    }

    // Start timer
    countDownTimer = new CountDownTimer(acReservation.getRemainingMilliseconds(), 100) {

        @Override
        public void onTick(long millisUntilFinished) {
            // Update/Show notification
            notificationManager.notify(NOTIFICATION_COUNTDOWN, createReservationActiveNotification((int)TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished)));
        }

        @Override
        public void onFinish() {
            // Clear notifications
            notificationManager.cancel(NOTIFICATION_COUNTDOWN);

            // Stop service
            stopSelf();
        }
    }.start();

    return super.onStartCommand(intent, flags, startId);
}

/*
Methods
 */

public Notification createReservationActiveNotification(int expInMinutes) {
    Notification.Builder notification = new Notification.Builder(getApplicationContext());
    notification.setContentTitle("Reservation");
    notification.setContentText("Your reservation expires in " + expInMinutes + " minutes");
    notification.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher));
    notification.setSmallIcon(R.drawable.car_icon);
    notification.setOngoing(true);
    notification.setPriority(Notification.PRIORITY_MAX);
    notification.setOnlyAlertOnce(true);
    return notification.build();
}

public void onEvent(ACEventBusButtonClick buttonClick) {
    if (buttonClick.getButtonAction() != null) {
        if (buttonClick.getButtonAction().equals(ACEventBusButtonClick.BUTTON_CANCEL_RESERVATION)) {
            notificationManager.cancel(NOTIFICATION_COUNTDOWN);
            countDownTimer.cancel();
            stopSelf();
        }
    }
}

这很简单。我将对象从Intent中取出并用它来计算毫秒数。然后我开始新的CountDownTimer，不断更新Notification。

在系统重新启动Service之前，它应该正常工作。它丢失了Intent额外数据，并在重新启动时在此代码行崩溃：

if (acReservation == null) {
    acReservation = (ACReservation) intent.getExtras().get("ACReservation");
}

日志说崩溃是因为Intent是null。所以当重新启动getExtras()时，我在空对象上调用Service。

我该如何解决这个问题？

Answer 1

从onStartCommand()返回START_REDELIVER_INTENT，而不是返回默认值的超级调用。

http://developer.android.com/reference/android/app/Service.html#onStartCommand(android.content.Intent，int，int）

当系统重新启动时，服务失去了它的意图

1 个答案: