When a user logs into my app I create an AlarmService to be fired in 10 minutes. In response to the alarm, I start a service that polls some data. After polling the service sets itself up with a new Alarm to fire again in another 10 minutes. This works great, but what exactly happens when the users phone gets shut off? Does the alarm wait until the phone is restarted? Or does the alarm get destroyed? How do I go about handeling this situation so the alarm can continue when the user restarts their phone?
you can't get an alarm work when the phone is off, but you can detect when the phone boot and do something in that moment, like calculate the time remaining to make something.
This link could help you:
Trying to start a service on boot on Android
Hope to help :)
If the user fully powers down the phone, your alarms are wiped out. Usually, the solution is to register a BroadcastReceiver to get control at boot time via the BOOT_COMPLETED broadcast, to go in and set up your alarm(s) again. Here is a sample app demonstrating this.
Related
I have a service that runs well but when phone goes to deep sleep , the service stop working .
I want to make use of some android class that makes the service to run everyday
at specific time ,??
i have tried wakelock but it drains the battery very fast for 24/24 cpu on
Any HELP ??
In case this becomes a bigger discussion then our comments. I'll list my answer here.
So your goal is to schedule a job with the alarm manager. Just make yourself a broadcast receiver class and register it on your app's startup. Then you will get code to run on each received notification.
If you need your service to run one time use an IntentService for efficiency instead of regular service.
Also, if you need to make sure it starts automatically then you should register for receiving of phone boot so that you can start your scheduled job again.
The link example:
Schedule a TimerTask at specific time once per day in a service in android
Better solution: you can use any of them alarm manager/jobscheduler/GCMNetworkManager
Create a alarm with looping every 24 hr interval.
That's all you need.
PS: Service will drain your battery.
I'm working on an app that has an IntentService that shows a Notification with showtimes for a local venue. I want the IntentService to be called every Fri at 5am or at boot on Friday morning.
What would be the best way to do this?
Right now I'm thinking of having a parent IntentService that will start at each boot and check what day it is and run the child service accordingly, but I don't know how to deal with a scenario where the user doesn't reboot.
Also, how would I run just the IntentService at boot and not the entire GUI?
Thank you
You can use the AlarmManager and use the setRepeating() method to set an Alarm that goes off every week at the same time.
Your booting requirement is probably not worth the effort, as very very few people reboot their mobile devices often. I've personally gone months without turning my phone off.
However, you don't need a parent service. You can do the checking of the day when the child service first starts up, and have it kill itself if its not Friday.
I'm have a widget that is being updated from a service. When the user then turn off the screen, the service stops and won't start to update the widget again when the user wake up the device. So on to my question, is there some way to "restart" the service when the user wake up the device? I know I can keep the service keep going when the screen is locked, but I think it would drain to much battery then... I have google'd alot but haven't found anything...
Thanks in advance!
EDIT: Okey, this is strange! Now somehow it does that automatically, so it's working now! Thanks anyway!
EDIT 2: Or, now I don't really think it's the screen lock that stops the service, cause it just sometimes stops randomly without crashdialog when I use the phone... Anyone know how I should do to fix that?
For a widget it usually doesn't make sense to keep a service running all the time, you usually update the widget periodically.
The easiest way to do this and to be battery efficient is to schedule an intent using AlarmManager and setAlarmInexactRepeating:
Schedule a repeating alarm that has inexact trigger time requirements; for example, an alarm that repeats every hour, but not necessarily at the top of every hour. These alarms are more power-efficient than the strict recurrences supplied by setRepeating(int, long, long, PendingIntent), since the system can adjust alarms' phase to cause them to fire simultaneously, avoiding waking the device from sleep more than necessary.
The intent should trigger a BroadcastReceiver which in turn should trigger your service to update the widget. Using IntentService is usually a good choice for that.
If you need more control over the intent scheduling, you can also set the alarms yourself in when the service is finished with updating the widget, and supply RTC or ELAPSED_REALTIME as the type of alarms. Both types won't wake up the device if it's sleeping. If the device is not sleeping (but locked) you'll effectively piggy back on other events that woke the device.
If you really need to update as soon as the device is unlocked, the ACTION_USER_PRESENT broadcast might be what you need, but I'd still recommend to implement that as an addition to scheduling a periodic update.
Yes this is Possible!
When the user turn off the screen You Have to handle BroadCast Receiver (http://developer.android.com/reference/android/content/BroadcastReceiver.html)
That handle to Stop service & the service stops and stop to update the widget,
when the user wake up the device you have to Receive Broadcast start to update the widget.
I think it would be The best idea to save more battery.
For More information Please Refer this Link
I have build a service to broadcast a timer data to various activities. Usually it runs ok without problems, but there are ocassions when android restarting it does not work as expected.
It has also three Broadcast receivers:
1 - Screen off event: in order to stop broadcasting timer data and setting an alarm in alarmanager for when the service ends, so I will be able to play end notifications for the users to attend.
2 - Screen on event: in order to continue broadcasting the timer data. I also cancel any preiously alarm pending.
3 - A receiver for alarms. This usually fires when screen is off, as explained in 1.
My service is started with startForeground and return START_REDELIVER_INTENT. AS the start intent has inicial timer date, I can recreate service status without problem. Broadcast alarm receiver and onStartCommand share the same handle intent routine to start or continue the service.
All this works perfect. For short timer ( < 30 min ) I dont find any problem. The screen can be on, off, change same times from on to off and from off to on. Also the activity can be in front or in back. I have toying with those all possible states. In all cases, my service and activity runs ok.
My problems comes when some timer are longer ( > 30 min , usually I set up for 35 min). There are sometimes that maybe due to memory reason Android kill me service. That is ok, as I understand Android does this in order to improve user experience. The problem is that when I goes to 'settings/application/services' I can see my service in 'restarting' state. I suspect this mean Android has not launched it yet and it is been sheduled. It show that state for long time (I have not had patient to say if it changes for more that other half hour....)
The problem is that when in that state, that can long for ever (I have been looking into it and the service is never started), the timer (in my watch) reach the timeout, the alarmmanager launch my intent, but as my service is not started yet and the broadcast not registered, I cann't do staff for time outs (playing notifications). So the user does not known the service timer has ended and it is a heavy problem.
It is very courious. As the service is killed in almost any run passed 30 min, while other services are not killed.
My question is: what exactly is it happening? How can I correctly handle this situation in order to detect alarms been fired correctly, or more to the point: how can I force my service to be restarted correctly?
For adding some help data:
My service does have very little memory compare to others, and also does not run long operations, it only uses handler.postdelayed("sendUpdatesToUI",250) when screen is on, and nothing when screen is off, only waiting for alarmmanager to send time out intent.
When time is reached, and user opens the activity, it received the timer data broadcast intent from service and as it see time is reached, then it stops the service.
I understand and accept user can kill the service when he wants, and I accept that. The problem here is not the user, but Android restarting the service.
When service killed, onDestroy is not invoked.
Using 2.3.4 version.
After lot of investigation I found the solution to my problem. It is all about startForeGround function. I was using:
startForeground(0,not);
while this looks good and it found in lot of examples around the web, the correct way to do it is not using 0, but any other random value:
startForeground(2765, not),
This solve the problem.
I know how to setup an alarm to fire repeatedly, but the alarm stops firing after my application is killed.
How do I make sure the alarm continues to fire as it was setup?
You can automatically restart your closed app Activity after a few
seconds using the OneShotAlarm approach described at
http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/app/OneShotAlarm.html
using a scheduled app (re)launch.
If you try to kill the integrated clock application, you'll see the alarm doesn't ring anymore (I had the problem with my HTC Desire).
That's because you can't keep any observer when the application is killed.
So you can't place any kill safe alarm.