Issue with cancelling the AlarmManager - PendingIntent

Question

I have an app which reminds people to do their tasks. So there is one PendingIntent, now the user can delete the alarm when he wants to. In this code, there is just one PendingIntent for multiple user alarms so I am confused on cancelling that particular alarm where the intent extras is "pill". The remaining alarms should not be cancelled. I have no clue on this problem. Hope I am clear. Thanks

Intent intent = new Intent(this, AlarmNotifyReceiver.class);
intent.putExtra("Name_pill", "pill");
sender = PendingIntent.getBroadcast(this,
DatabaseConstants.NOTIFICATION_ID + 1, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP,cal.getTimeInMillis(), sender);
updateTheFlag(pillName[(pillName.length-1)]);

Answer 1

According to the Android documentation, in order to stop an alarm, you should create an Intent with the same data, but not necessarily the same extras:

public void cancel (PendingIntent operation)

Remove any alarms with a matching Intent. Any alarm, of any type, whose Intent matches this > one (as defined by filterEquals(Intent)), will be canceled.

filterEquals(Intent)

public boolean filterEquals (Intent other)

Determine if two intents are the same for the purposes of intent resolution (filtering). > That is, if their action, data, type, class, and categories are the same. This does not compare any extra data included in the intents.

Answer 2

As I stated in my comment, it appears that you simply need to recreate the exact same PendingIntent object, and put the same Extras into it. Then, you call

am.cancel(sender);

And your specific alarm should be canceled. I can't find a better way of doing it, personally. I found this information to confirm my expectation elsewhere.

It reads:

Repeating alarms have to be cancelled to stop them. AlarmManager provide a cancel() method that requires the same intent class with which the intent is created. This is how you can cancel the alarm.

alarmManager.cancel(pendingIntent);

Note the pendingIntent object does not need to be same object. The intent fields like action, class, category etc should be same while creating the alarm. The intent is used to identify the alarm to cancel it.

It is in the context of repeating alarms, but one-time alarms should be canceled in the same manner, if I am not mistaken. I am unable to test it more thoroughly on my own because I am at work, but this should work.

Answer 3

I think the requestCode parameter in getBroadcast() needs to be mentioned. I agree that all the alarms will be canceled matching with the given Intent. But an alarm can be made to be unique by using unique requestCode when defining the PendingIntent for canceling. So only those alarms will be canceled which has the same intent and requestCode:

int TIMER_1 = 1;
int TIMER_2 = 2;
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
Intent i = new Intent(this, AppReciever.class);
i.putExtra("timer", "one");
PendingIntent pending = PendingIntent.getBroadcast(this, TIMER_1, i,
            PendingIntent.FLAG_CANCEL_CURRENT);
Calendar cal = Calendar.getInstance();
am.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), pending);

then check that the PendingIntent exist according to this:

PendingIntent pending1 = PendingIntent.getBroadcast(this, TIMER_2, i, 
                PendingIntent.FLAG_NO_CREATE);
boolean alarmUp = (pending1 != null);

alarmUp will be false (note FLAG_NO_CREATE is used not to create a new one if not exist) so trying with same requestCode:

PendingIntent pending2 = PendingIntent.getBroadcast(this, TIMER_1, i, 
                PendingIntent.FLAG_NO_CREATE);
alarmUp = (pending2 != null);

alarmUp will be true, now trying with a new intent contains different extra:

Intent i2 = new Intent(this, AppReciever.class);
i2.putExtra("timer", "two");
pending2 = PendingIntent.getBroadcast(this, TIMER_1, i2, 
                PendingIntent.FLAG_NO_CREATE);
alarmUp = (pending2 != null);

alarmUp will be true as well since the i and i2 are the same although the extra is not, so now you can remove this alarm:

am.cancel(pending2);

Answer 4

So there is one pending intent,now the user can delete the alram when he wants to. Ib this code there is just one pending intent for multiple user alarms so I am confused on cancelling that particular alarm where extras is pill

intent.putExtra("Name_pill", "pill");

The extra wont wont work to cancel your pending intent .

pendingIntent.cancel() will only remove that pending intent which triggered with same filterEquals(Intent) and that method is not compare any extra data given to intent .

this is the contain from developer site of android filterEquals(Intent)

Determine if two intents are the same for the purposes of intent resolution (filtering). That is, if their action, data, type, class, and categories are the same. This does not compare any extra data included in the intents.

if we consider your scenario , when you will pass that Extra to intent at that time you only need to save unique ID in some sharedpreference which given in parameter and one thing your should keep in mind that ID has to be an unique .

and and when you suppose to cancel that alarm , just pass same intent with that saved ID and cancel that pendingintent .

Create

preference_saved_value =  DatabaseConstants.NOTIFICATION_ID + 1
sender = PendingIntent.getBroadcast(this,
preference_saved_value, intent,
PendingIntent.FLAG_UPDATE_CURRENT)

CANCEL

sender = PendingIntent.getBroadcast(this, 
preference_saved_value, intent,PendingIntent.FLAG_UPDATE_CURRENT);  
sender.cancel()

Answer 5

As it's stated in android documentation pending intents with intent that are equivalent as per Intent.filterEquals but have different request code are considered different:

If you truly need multiple distinct PendingIntent objects active at the same time (such as to use as two notifications that are both shown at the same time), then you will need to ensure there is something that is different about them to associate them with different PendingIntents. This may be any of the Intent attributes considered by Intent.filterEquals, or different request code integers supplied to getActivity(Context, int, Intent, int), getActivities(Context, int, Intent[], int), getBroadcast(Context, int, Intent, int), or getService(Context, int, Intent, int).

So, you can assign different request code and cancel the pending intents base on them and forget about the extra.

There was an interesting scenario that I figured out this behavior:

I scheduled an alarm in my code and run it on the device but never canceled it. Then I changed the request code and run it again. So a new alarm was created. I canceled the new alarm but the alarm was still executing from previous code. I get confused why the alarm is not canceled. After I found out it's from the previous code with different request code I uninstalled the app and installed it again and problem was solved.