通知应在满足情况后停止

Question

如果数组中有一些数据，则该应用程序将通知每分钟，但是一旦数组为空，通知应停止，但不会停止。我的数组中的数据来自Firebase实时数据库。

这是我的代码。它在 addChildEventListener 内部。

Listeth 是数组。我可以很好地调用数据库中的数据。

if (listEth.contains(null)){
     // it will do nothing if there is no data
} else {
   NotifyUsers();      // notify every 24 hours
   notification();     // 
}

这是针对我的 AlarmManager

public final void NotifyUsers(){
        Intent intent = new Intent(this, NotifyPendingAssignments.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this,
                2, intent, PendingIntent.FLAG_IMMUTABLE);
        AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);

        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
                60000, pendingIntent);  //set repeating every 1 min
    }

这是数据的方式，

databaseEth.addValueEventListener(new ValueEventListener() {
     @SuppressLint("NotifyDataSetChanged")
     @Override
     public void onDataChange(@NonNull DataSnapshot snapshot) {
         for(DataSnapshot dataSnapshot : snapshot.getChildren()){ 
             assignmentEth assignmentEth = dataSnapshot.getValue
                  (com.example.timemanagementapp.assignmentEth.class);
             listEth.add(assignmentEth);
         }
         myAdapterEth.notifyDataSetChanged();
     }

     @Override
        public void onCancelled(@NonNull DatabaseError error) {
     }
});

我尝试添加另一个通知频道，该通知通道将在用户打开时不断通知，并在数组为空时停止。有用。

private void notification() {
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            NotificationChannel channel =
                    new NotificationChannel("eth", "eth", NotificationManager.IMPORTANCE_DEFAULT);

            NotificationManager manager = getSystemService(NotificationManager.class);
            manager.createNotificationChannel(channel);

            NotificationCompat.Builder builder = new NotificationCompat.Builder(this, "eth")
                    .setContentText("New Assignment")
                    .setSmallIcon(R.drawable.ic_baseline_notifications)
                    .setAutoCancel(true)
                    .setContentText("You have new assignment in ETH");

            NotificationManagerCompat managerCompat = NotificationManagerCompat.from(this);
            managerCompat.notify(120, builder.build());
        }
    }

但是我需要的是向广播castreceiver （notifyusers（））通知，即使应用程序不打开，它也会通知

这是我的 createNotificationChannel（）

private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

            CharSequence name = "notifyPendingAssignment";
            String description = "You have pending assignments in ETH";

            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel("notifyPendingAssignment", name, importance);
            channel.setDescription(description);
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }

and> and> and>和这是我的 createNotificationChannel（）的广播员

public class NotifyPendingAssignments extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, "notifyPendingAssignment")
                .setSmallIcon(R.drawable.icon_notif)
                .setContentTitle("Pending Assignment")
                .setContentText("You still have pending assignments.")
                .setPriority(NotificationCompat.PRIORITY_DEFAULT);

        NotificationManagerCompat notificationManagerCompat = NotificationManagerCompat.from(context);
        notificationManagerCompat.notify(202, builder.build());
    }
}

，这是我的 notifyuser（）

public final void NotifyUsers(){
        Intent intent = new Intent(this, NotifyPendingAssignments.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this,
                2, intent, PendingIntent.FLAG_IMMUTABLE);
        AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);

        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
                60000, pendingIntent);  //set repeating every 1 min
    }

Answer 1

我通过使用 notifyuser（）移动if其他条件并在该条件内设置AlarmManager来解决此问题。

if (listEth.isEmpty() || listEth.contains(null)){
      Toast.makeText(AssignmentListEth.this, "There is no Pending Assignment",
            Toast.LENGTH_SHORT).show();
      alarmManager.cancel(pendingIntent);
      pendingIntent.cancel();
} else {
     alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
                    60000, pendingIntent);  // every 1 minute
}