I have an application which once the user runs the app it has a long process to run, such as downloading needed files and setting it all up and what not. I would like to move the process to the background and show a notification in the status bar while the process is running.
What would my best strategy be to keep the process alive while downloading the files and what not. I've read about services, but have also heard they're easily killed? Should I use a service or should I just run a thread with maximum priority and just throw a notification up and close it when the process is over?
What's best thank you for any help. Process by the way is about ten minutes no longer than it takes to download a rom in rom manager basically just want that same setup thank you for any help.
It sounds like a Foreground Service is exactly what you need. When you create it, a notification is placed in the status bar to tell the user that it is running. The service is also given high priority so that it will not be canceled.
From the documentation for the Foreground flag:
public final void startForeground (int id, Notification notification)
Make this service run in the foreground, supplying the ongoing notification
to be shown to the user while in this state. By default services are background,
meaning that if the system needs to kill them to reclaim more memory (such as to
display a large page in a web browser), they can be killed without too much harm.
You can set this flag if killing your service would be disruptive to the user,
such as if your service is performing background music playback, so the user
would notice if their music stopped playing.
You can look at the rest of the documentation here.
A service is exactly what you want. You can specify how high of priority your service is when you create it (see #theisenp's post).
As for moving your Activity to the background and reopening it later - I recommend starting the service, then actually stopping your app using the finish() method. Then, once the service is complete, relaunch your activity with Intent, or broadcast an Intent that can be handled by a BroadcastReceiver.
Related
I've read that I should call
startForegroundService(intent)
if I want to properly start a service that can run as a foreground service. But how should I think if I want it to start without it being a foreground service but potentially becoming one later on? Some info on how we have it right now:
We have an App which uses a service for many tasks. It performs all of these task when the user interacts with the app in the foreground but depending on if the user has enabled a certain feature we want to keep performing these tasks in the background. So when the app is launched (and obviously is in foreground) we start the service using
startService(intent);
When the app transitions into background we check whether the feature is enabled, and if so, run startForeground(id, notificiation); which effectively adds the non-removable notification out in the OS and the service keeps on running. When the app goes back into foreground we call stopForeground(true). If the feature isn't enabled the service will never be set as a foreground service and we won't try to perform these tasks in the background.
So my question is: Is this sufficient to get the "full foreground service performance"? Or am I losing something by not calling startForegroundService(intent)? My impression is that we actually do have a fully working foreground service but I'm getting confused when I read statements that foreground services must be started using startForegroundService(intent) which we're not doing. If we really need to use startForegroundService(intent), the only solution I can think of would be to initially start a normal instance of the service and when the app enters background we start a new one using startForegroundService(intent). But do we need to do this or is running startForegund(id, notification) on a service started using startService(intent) sufficient to achieve a foreground service?
NOTE: One difference I find is that if the application itself is in background when start the service I then need startForegroundService(intent) for API >= 26. In our case we always start the service when the app is in foreground. I do however recall some instances where I've seen the exception thrown when we try to start the service using startService(intent), somehow the app (very very rarely) still think it's in background (perhaps something from the OS comes up just when app is launched). So if I catch when that happens I could run startForegroundService(intent) to start the service. But is it possible to run stopForeground(true) on that service when the app comes back into foreground? Or is it bound to be a foreground service forever since we started it that way?
Seems like you don't have to call startForegroundService and startService is sufficient:
If your service is started (running through Context#startService(Intent)), then also make this service run in the foreground, supplying the ongoing notification to be shown to the user while in this state. By default started services are background, meaning that their process won't be given foreground CPU scheduling (unless something else in that process is foreground) and, if the system needs to kill them to reclaim more memory (such as to display a large page in a web browser), they can be killed without too much harm. You use startForeground(int, Notification) if killing your service would be disruptive to the user, such as if your service is performing background music playback, so the user would notice if their music stopped playing.
From Documentation
I read your question multiple time and I think (hopefully) the answer to your question is :
According to the official document of Android 8.0 Background Execution Limits:
Android 8.0 introduces the new method startForegroundService() to
start a new service in the foreground. After the system has created
the service, the app has five seconds to call the service's
startForeground() method to show the new service's user-visible
notification. If the app does not call startForeground() within the
time limit, the system stops the service and declares the app to be
ANR.
So, make sure you have started ongoing notification by calling startForeground (int id, Notification notification) in the onCreate() method of your service.
Note: Apps targeting API Build.VERSION_CODES.P or later must request the permission Manifest.permission.FOREGROUND_SERVICE in order to use this API.
And there is great medium article posted by Maciej Witowski that help you understand how really new services API works :
https://proandroiddev.com/pitfalls-of-a-foreground-service-lifecycle-59f014c6a125
I created a music app on the android platform but when I let it run for a few minutes when the screen turned off, the app turned off and didn't play the music anymore. So how do I extend the time the application runs when the screen is turned off?
I'm assuming that you are running the Service to play music in the background. So, when OS thinks that the mobile device has to reduce the battery consumption, it just kills your service sometime after it was run.
Now, what you can do to avoid this, is running that in foreground instead. Because then that service is kind of marked as useful by the user so that doesn't get killed unless the user themselves do that.
Find out more about How to set a Service to run in foreground here in the documentation
The above link clearly mentions:
a music player that plays music from a service should be set to run in the foreground
But keep in mind that any service to accomplish any task should run in the foreground only if the user is aware that the task is being accomplished.
You should only use a foreground service when your app needs to perform a task that is noticeable by the user even when they're not directly interacting with the app.
And for that reason, you must show a notification mentioning that this service is being run in the foreground, to accomplish this task, so that the user can be in knowledge of that.
A foreground service must provide a notification for the status bar, which is placed under the Ongoing heading. This means that the notification cannot be dismissed unless the service is either stopped or removed from the foreground.
I'm developing an app to track the user location when they hit the button Start. I implemented a service to record the location with the LocationListener and it works well but I have being done some heavy testing and when I open some applications my app and service are getting killed by android randomly.
But I downloaded an app called Wikiloc and doing the same heavy test, opening multiple apps this app is never getting killed and I see the app creates a notification that can't be dismissable. Can it be related to the fact that the app is never killed by the system?
How can acheive this in my app? Do I have to do the notification trick? If so, how it is implemented?
Take a look at the documentation for the Android Service's startForeground(int, Notification) here. According to the documentation:
Make this service run in the foreground, supplying the ongoing notification to be shown to the user while in this state. By default services are background, meaning that if the system needs to kill them to reclaim more memory (such as to display a large page in a web browser), they can be killed without too much harm. You can set this flag if killing your service would be disruptive to the user, such as if your service is performing background music playback, so the user would notice if their music stopped playing.
You call startForeground inside your Service's onCreate method.
I am working on an application which need to show notification constantly.
I've a service to show the notification every seconds.
When the resources goes low android is killing my service.
I've given the return START_STICKY from onStartCommand().
So after some time the service is getting restarted.
But in the mean time the notification look stoped.
I red somewhere that it is possible for a service showing notification prevented from getting stoped by android. I dint get any example for it.
Use
startForeground(int,Notification);
in onCreate of service. It requires a notification number and a notification object which it will display in the notification bar.
To remove the notification, use
startForeground(0,Notification);
As written above you need to use startForeground(int,Notification) method to aware user about your service. It also get more privilage for it.
You can read more about it here (example inside).
There is no way to completely stop it from ever being killed. Making it a foreground service helps. Returning start_sticky means it will be restarted if it is stopped (so it should do a startService on itself in its onCreate to make sure it restarts and not just gets recreated). But Android has the right to kill any service at any time due to resources.
Update:
You can use Foreground Service in the scenario. From the docs:
A foreground service is a service that's considered to be something the user is actively aware of and thus not a candidate for the system to kill when low on memory. A foreground service must provide a notification for the status bar, which is placed under the "Ongoing" heading, which means that the notification cannot be dismissed unless the service is either stopped or removed from the foreground.
In my knowledge there is no bulletproof way of preventing your service from being stopped by the android system. If the device is critical on memory/resources then your service has to be stopped for GC. This is also not recommended because your service will drain the device battery.
I am currently writing my first Android application and I keep running into references to background and foreground services. Since I intend on using a service in my application I was hoping to get a clarification between the two and how they are used.
Perhaps this will answer your question:
A started service can use the startForeground API to put the service
in a foreground state, where the system considers it to be something
the user is actively aware of and thus not a candidate for killing
when low on memory. By default services are background, meaning that
if the system needs to kill them to reclaim more memory (such as to
display a large page in a web browser), they can be killed without too
much harm.
More info can be found here
Foreground: The process relies on onPause() and onResume()...i.e you play music player and pressing pause and play
Background: The process which runs without user interaction i.e receiving a message, incoming call, receiving mails, or setting alarms. The method used here is onStart() and onStop().
For example, check it on your phone. Create an alarm at 6:30am. When the system clock reaches 6:30am it fires. In order to kill the alarm service, just go to menu-->settings-->application-->Running service-->click stop service. It stops the alarm service even when your system reaches the time it won't fire.
Foreground Service is used when User is interaction with application and when Service is doing something visible to user. Background Service is used when even user close application (discard from recents) and when Service is doing something not visible to user like downloading data from server, load data from a ContentProvider etc.. And Foreground Service is less likely to be killed by system on low memory.