I found a lot of examples and questions regarding how to fire an alarm using AlarmManager (both periodical or single), but nothing similar to what I need.
My user can schedule a certain number of events (i.e. things to do), with a single-shot alarm for each of them to be fired one day before the scheduled start (showing a notification). This is easy.
My problem is that this scheduled start can be changed, thus the alarm should be moved too.
I was thinking to delete the old alarm, and to create a new one considering the new scheduled start. Knowing that I can delete an alarm using alarmMgr.cancel(alarmIntent), how can I delete the specific alarm related to the rescheduling event? Should I make each alarmIntent unique in some way?
Or there is a better way that I didn't consider (except using Google Calendar APIs to schedule and reschedule an event there, and making it managing the notification)?
While scheduling an alarm using set() API
public void set (int type, long triggerAtMillis, PendingIntent operation)
in the last argument you can mention a request code using getBroadcast
public static PendingIntent getBroadcast (Context context, int requestCode, Intent intent, int flags)
an example for this would be :
alarm.set(AlarmManager.RTC_WAKEUP, time, PendingIntent.getBroadcast(mContext, id, intentAlarm, PendingIntent.FLAG_UPDATE_CURRENT));
When you want to cancel or reschedule you can use the 'id' to specify which alarm.
Related
Following code works perfectly for Activity:
Intent intent = new Intent(context, MyActivity.class);
PendingIntent operation = PendingIntent.getActivity(context,
0,
intent,
PendingIntent.FLAG_UPDATE_CURRENT);
alarmmanager.setExact(AlarmManager.RTC_WAKEUP,
startTime.getTimeInMillis(),
operation);
However, when I do the same thing for IntentService, It works only if startTime and time I set alarm are on the same day. e.g. If I set the alarm today for 5 PM, it will be executed but when I set the alarm today for 5 PM tomorrow, it will not be executed. If this was Activity then it works for both cases.
Intent intent = new Intent(context, MyService.class);
PendingIntent operation = PendingIntent.getService(context,
0,
intent,
PendingIntent.FLAG_UPDATE_CURRENT);
alarmmanager.setExact(AlarmManager.RTC_WAKEUP,
startTime.getTimeInMillis(),
operation);
How to solve this?
The goal here I am trying to achieve is to execute IntentService every day at the exact time.
The goal here I am trying to achieve is to execute IntentService every day at the exact time.
Google has made this progressively harder from release to release. See Android AlarmManager setExact() is not exact. There could be two ways to solve this for your case:
you start an activity, which starts the service (as starting an Activity seems to work for you)
you use either setExactAnd... or setAlarmClock. setAlarmClock also triggers in the new "doze" mode, see https://stackoverflow.com/a/47049705/1587329.
Another way would be to re-think why and if you really need this... or if a JobScheduler could not fit your purpose more easily.
add replace your line with this line :
alarmmanager.setRepeating(AlarmManager.RTC_WAKEUP,
startTime.getTimeInMillis(),
operation);
it will repeat on specific interval you set in alarm manager
Replace the AlarmManager with this code:
alarmManager.setRepeating(AlarmManager.RTC,
timeMills,
AlarmManager.INTERVAL_DAY,
pendingIntent);
Worked for me.
HERE IS a DETAILED ANSWER check link in the bottom for more details.
Hope this will help. Your issue can be probably related to android versions too so do check the link for more details
app gets an instance of the AlarmManager and sets an alarm using a PendingIntent. More on usage and setting alarms is coming in the next section. The AlarmManager is the app side interface to the backing AlarmManagerService. It abstracts the details of the Binder interface, used to communicate with the system process (system_server) hosting the AlarmManagerService. These two components manage the alarm(s) the app has set and will send the PendingIntent correctly. This manager/service architecture is used throughout Android framework and is done for security and isolation purposes. The system_server process is running with privileges which normal apps do not have. If you are unfamiliar with Android’s use of permissions, see this article for more details on app processes and user IDs. These extra permissions are what allows system_server to access the underlying kernel alarm driver. The alarm driver is what manages setting alarms to wake up the device regardless of the sleep state of the SoC.
When the alarm is triggered the device is awakened (if asleep) and the AlarmManagerService is notified of an alarm expiring. It will then send the PendingIntent accordingly. This will cause the appropriate component within MyApp to be activated. If MyApp has not been started or its process is not cached, it will be started so the component can be activated.
basic usage will be as
public class MyActivity extends Activity {
...
private AlarmManager mAlarmMgr;
...
public void onCreate(Bundle savedInstance) {
...
mAlarmMgr = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
...
}
...
}
let’s create a PendingIntent for our MyActivity using the component name.
Intent alarmIntent = new Intent(context, MyActivity.class);
PendingIntent pend = PendingIntent.getActivity(context,
0,
alarmIntent,
PendingIntent.FLAG_UPDATE_CURRENT);
Now that we have our PendingIntent and the AlarmManager, we can set our alarm so our Activity is triggered when the alarm has expired. To do this, we need to figure out when we want our alarm to go off and whether it should wake up the device or just be delivered the next time the device is awakened. Remember, we have two different ways of specifying time for our alarms: elapsed time or calendar (RTC) time. So our options are ELAPSED_REALTIME, ELAPSED_REALTIME_WAKEUP, RTC or RTC_WAKEUP. The _WAKEUP variants are our “aggressive” alarms where we want the device to come out of low power to call our app back. For our sample app, let’s set this up in a custom BroadcastReceiver and have it trigger our Activity about 30 seconds after the device is booted
public class MyBootReceiver extends BroadcastReceiver {
public void onReceive(Context, context, Intent intent) {
...
AlarmManager alarmMgr =
(AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
long wakeTime = SystemClock.elapsedRealtime() + 30000;
alarmMgr.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, wakeTime, pend);
}
}
Now when our device boots and the BOOT_COMPLETED broadcast is sent, our app’s process will be started and our receiver will set an alarm to trigger our Activity to be launched about 30 seconds later. Note that on Android 3.1 devices or newer, you must first manually launch your app before the BOOT_COMPLETED.
CREDIT GOES to writer of this BLOG
if you want to set the repeated alarm using SetExact you are bound to stop all other pending intents on the same time check this link for that here are many examples of how to do it! again credit goes to this writer
If I allow my user to schedule a notification using AlarmManager, and then they schedule another notification using the same code, will the first alarm be overridden? Or will both alarms be set?
When creating a pendingIntent you have to include an id:
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, ID , intent, Flags)
If the number in the ID location is always the same, then the alarm will be overridden. If it is the same then it will not be.
You can use the same code, as long as the ID is different. You can achieve this in many ways, like creating an ID based on the time you schedule the alarm for, as you may not need two alarms for the same time.
I'm developing an app which you can schedule your time and It reminds you on time just like google calendar. I use AlarmManager class and set a Repeating task to check Database every one minute and see if there is any alarm on that time or not.
#Override
public void onReceive(Context context, Intent intent) {
Calendar now = Calendar.getInstance();
doRepeatingWorks(now.getTimeInMillis()); // Like Checking if one day passed to do some tasks
checkDbIfThereIsSomeSchedule(now);
}
And I call this to start alarm manager:
public void setAlarm(Context context) {
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, 0);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), G.ALARM_CHECK_INTERVAL_MILIS, pendingIntent);
}
But it's inaccurate and sometimes I figure out that the task killer apps kill my alarm and make it totally worthless.
Although using a foregroundService is battery consuming and it goes on user's nerve with the notification.
Is there any solutions or alternatives for this problem?
I use AlarmManager class and set a Repeating task to check Database every one minute and see if there is any alarm on that time or not
That is a truly awful approach. This sort of behavior is precisely why Doze mode and app standby were added in Android 6.0.
Is there any solutions or alternatives for this problem?"
Schedule an alarm event for first event. When you get control, notify the user about the event, then schedule an alarm event for the next event in sequence. If the user adds a new event that is sooner than your first event, cancel the previous alarm and schedule one for the new first event.
You don't need to check there is an alarm in each 1 min. I hope this post helps you - Scheduled Alarm Manager not working Android
I'm trying to create a function in my App, which notifies the user at the expiration day of his rented books. I'll work with checkboxes in a listview, as below:
(Dates are for show purposes only)
Now i'm wondering how can i do it the best way. I'm having experiences with AlarmManager and BroadcastReceivers, but I didn't get a clear flowchart yet.
Thats because I need to set an specific alarm to each book and cancel that specific alarm when requested. Also, it needs to reactivate all Alarms when device is restared (by calling BOOT_COMPLETE broadcast).
PS.: Alarms will usually be set to one week after current date.
PS2.: Can I use Calendar to do it? I mean, this way i wouldn't have to reactivate all alarms, or calculate (expirationDate - currentDate) in millis.
Can someone, who has an idea, try to show me the way? Thanks!
I think the key would be to give each and every book its own alarm id as soon as you set the alarm for this book for the first time.
Then you should keep a list of the running alarm ids and timestamps (maybe in SharedPreferences).
With a method like this you can cancel a specific alarm with regards to its alarm id:
public static void cancelAlarm(Context context, int alarmId) {
PendingIntent pi = PendingIntent.getService(context, alarmId,
new Intent(context, YourService.class),
PendingIntent.FLAG_NO_CREATE);
if(pi!=null) {
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
am.cancel(pi);
}
}
When you receive the BOOT broadcast, you can get the list of alarm ids together with timestamps from SharedPreferences and start all the alarms with their respective alarm ids
I am adding an event to my schedule
list and alarm has been fixed to that
event. I have to repeat alarm for
every one minute, from the before five
minutes of event ending time. In below
conditions I have to remove or cancel
alarm for particular event.
When I delete event from my schedule.
Event placed in schedules but I don't want alarm for event.
I am following concepts like sqlite database, Alarm manger, Services. I am confusing little bit using Services and pendingIntent. So, please suggest me the right way to approach my requirement.
You need to use the method cancel(...) from AlarmManager, using the same PendingIntent you used to set the alarm. Example:
this.getAlarmManager().cancel(mAlarmPendingIntent);
(this refers to the Activity or the Service from which you are cancelling the alarm).
Here is the link for the API.
Create the PendingIntent as:
mAlarmPendingIntent = PendingIntent.getActivity(this, requestCode, intent, flags);
The API doc for PendingIntent is here.