Develop Reference

Android is killing activity while the service controlled by it lives on

I have an app which has a single activity which has a checkbox the starts and stops a foreground service. The activity also has some other settings which control that service.
The problem is that after some time navigating other apps the service continues to run fine but the activity gets killed. If I restart the activity the checkbox will be set to default, off. If I switch it to on, a second service starts, while the first one is still running and can't be controlled anymore.
I can't figure out how to handle this situation. It's necessary for the service to run indefinitely and there doesn't seem to be anyway to keep the activity from dying. Maybe there's a way for the new activity to find the old service?

Try to kill the service in OnPause() method of your activity .that solve my problem few times ago.

To check if particular service is running, write the below method your activity, and call it when you want to check the state of the service
private boolean isMyServiceRunning(Class<?> serviceClass) {
ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
if (serviceClass.getName().equals(service.service.getClassName())) {
return true;
}
}
return false;
}

"service continues to run fine but the activity gets killed"
services are given more importance than activities, if android where given a choice to kill an activity or a service it always kill an activity first.
"a second service starts"
services can only be started once no matter how many times you start a service.
"checkbox will be set to default"
use sharedpreferences to persist values.

Foreground service being stopped by Android does not restart later

I have a Foreground Service for my app, which must run the whole time and never stops. While I was testing it few times, it seems after 3-4 days Android decides it just to stop it, and never restart it again, and in my Activity I have a check for the service if its running, and if it isnt to start it.
Even though, the service is not starting, and I can't debug it, because this is not happening immidiatelly.
So this is my check, is there something wrong in it?
if (!isMyServiceRunning(MyService.class)) {
startService(new Intent(this, MyService.class));
}
private boolean isMyServiceRunning(Class<?> serviceClass) {
ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
if (serviceClass.getName().equals(service.service.getClassName())) {
return true;
}
}
return false;
}
I call this check in onResume() of the Activity, and I can't just run it everytime when the activity starts, because I have a constantly running Thread in the service, which will get more than one instance if started several times...
So here is what I want:
Either have more reliable way to check for the service if its running
or
Just start the service every time the activity starts, to prevent problems, and the thread inside of it must always have just 1 instance (I have already declared is as static)

You can make your service Bindable and bind your Activity to the service when the Activity starts/resumes. This way you will be sure the service is running. But I think you have a problem with your service. My I ask you to post more information about the service? It is not normal the OS to kill a foreground service with no traces.

onPause() method issue on kitkat 4.4

My app contain lock screen which will be come up when app brought from background.
I am facing a problem particularly onwards kitkat 4.4.
While app goes in background, i am checking that the Is application going in background? in onPause() method of activity which was on foreground by following code.
private boolean isApplicationBroughtToBackground()
{
ActivityManager am = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);
List<RunningTaskInfo> tasks = am.getRunningTasks(1);
if (!tasks.isEmpty()) {
ComponentName topActivity = tasks.get(0).topActivity;
if (!topActivity.getPackageName().equals(getPackageName())) {
return true;
}
}
return false;
}
I am calling above method in onPause() and on basis of returning value i am taking decision to show lock screen.
As per my observation this method is returning true in below 4.4 OS, but its returned false onword 4.4.
If i make a call in onStop() method i am getting true in all the cases.
I want to know whats the changes made in kitkat in context of activity life cycle?
Need to know reason why its behaving differently in kitkat?

Close the service from the library only when the entire app goes to the background

I searched a lot in the net about it, the solutions are based on onPause and onDestroy. I want to give a library to a developer who just needs to paste a few lines of code from the library in his app which will enable the developer to create a service and destroy it when his entire app is in the background.
Does the Android OS send some kind of signals or intents when the app or the activity is changed (other than onPause or onStop method), so that i can catch that in a broadcast receiver from my library and do some actions.

If you know the package name of your app, try this (put this following snippet in the onCreate method of your app):
ActivityManager am= (ActivityManager) this.getSystemService(ACTIVITY_SERVICE);
Then,
boolean exit = false;
while(!exit)
{
List<RunningTaskInfo> taskInfo = am.getRunningTasks(1);
ComponentName componentInfo = taskInfo.get(0).topActivity;
if(!componentInfo.getPackageName().equals("Your package name"))
{
//Do your work here
exit = true;
}
}
When you start your app, this will be put into componentInfo. The taskInfo.get(0).topActivity will return the activity in the foreground. Hence you can know that your app has gone to the background by comparing package using the second code snippet.
Note:Put this second code snippet in an Asynctask so that the checking of whether the app has started can be done in the background.

Android: test from a service, if an Activity is running.

I have a service that runs in background. I I wish it could perform an action, only if a certain activity is running. How can I test, from a service, if the activity is running?

You can use the Package Manager and the Activity Manager:
PackageManager: Class for retrieving various kinds of information related to the application packages that are currently installed on the device. You can find this class through getPackageManager().
ActivityManager: Interact with the overall activities running in the system.
But, a more simple approach would be: When starting your Activity (onCreate/onResume), send a message with service.send(..) or an Intent with service.onStartCommand(..) so the service knows that your particular Activity has been started.

Maybe you can do it the other way around, sending intent from your activity to the service.
For example, you can send an intent on the activity onResume, telling your service the activity is live, and another on onPause, telling the service the activity has stopped

Use the below method with your package name.It will return true if any of your activity is in foreground.
public boolean isForeground(String myPackage){
ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
List< ActivityManager.RunningTaskInfo > runningTaskInfo = am.getRunningTasks(1);
ComponentName componentInfo = runningTaskInfo.get(0).topActivity;
if(componentInfo.getPackageName().equals(myPackage)) return true;
return false;
}