NotificationManager.cancel(id) is not working inside a broadcast receiver

Question

Android: I am trying to cancel a notification from the notification bar after a package being installed. What I am doing is the following:

public class MyBroadcastReceiver extends BroadcastReceiver {

    private static final String TAG = "MyBroadcastReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (Intent.ACTION_PACKAGE_ADDED.equals(action)) {
            Uri data = intent.getData();
            //some code goes here
            //get the id of the notification to cancel in some way
            notificationhelper._completeNotificationManager.cancel(id);     
        }
    }
}

where

public class notificationhelper {
    public static NotificationManager _completeNotificationManager = null;

    public void complete() {        
        if (_completeNotificationManager == null)
            _completeNotificationManager = (NotificationManager) _context.getSystemService(Context.NOTIFICATION_SERVICE);
            
        Notification notification = new Notification(
            R.drawable.notification,
            _context.getString(R.string.notification),
            System.currentTimeMillis());
        notification.flags |= Notification.FLAG_AUTO_CANCEL;
        notification.flags |= Notification.FLAG_NO_CLEAR;
        _completeNotificationManager.notify(TEXT, id, notification);
    }
}

But the notificationhelper._completeNotificationManager.cancel(id) does not work. I tried to use notificationhelper._completeNotificationManager.cancelAll(); and it works. What I am doing wrong?

Answer 1

In my experience, you can't cancel all notifications with a particular ID, regardless of tag.

That is, if you create two notifications like so:

notificationManager.notify(TAG_ONE, SAME_ID, notification_one);
notificationManager.notify(TAG_TWO, SAME_ID, notification_two);

Then, notificationManager.cancel(SAME_ID) won't cancel either of them! I suspect that this is because the "tag" field, if unspecified in notify() and cancel(), defaults to null, which you have to cancel explicitly.

So, to cancel these two notifications, you have to call:

notificationManager.cancel(TAG_ONE, SAME_ID);
notificationManager.cancel(TAG_TWO, SAME_ID);

In your case, you're supplying "TEXT" as the tag but cancelling just using the id, which defaults to using tag=null.

So, either don't provide TEXT as your tag:

_completeNotificationManager.notify(id, notification);

Or, if you need separate notifications and don't want them to clobber each other, keep track of the active tags:

_completeNotificationManager.notify(TEXT, id, notification);
collectionOfActiveTags.add(TEXT);

...

for (String activeTag : collectionOfActiveTags)    
    notificationhelper._completeNotificationManager.cancel(activeTag, id);

I wish that what you're trying to do was supported, as it seems that it should be.

Answer 2

Well this is probably irrelevant at this point, but it should be posted here so that people like me dealing with the same problem might find the solution.

If NotificationManager.cancel() isn't working, try changing the ID for the notification.

notificationManager.notify(NOTIFICATION_ID, notification);

When I changed NOTIFICATION_ID from 1 to [RANDOM_NUMBER], it magically started working. I assume that 1 is somehow reserved, although there is no note in any documentation...

An of course make sure you use the same NOTIFICATION_ID to cancel:

notificationManager.cancel(NOTIFICATION_ID);