My application will launch 3rd party map activity and set the place. Once user press back from Map activity, it will return to previous activity.
Once i quit the application, the map activity and other process will be keep running. i would like to close them. How should i do?
Thanks in advance
Try Launching the foreign activity with FLAG_ACTIVITY_NO_HISTORY
A process is not the same as an Activity, and it's not your concern if a process (even your own) remains alive when not in use, as Android will dispose of it when appropriate.
You should never try to kill foreign processes (you can't anymore anyway), and the situations where you want to kill or end your own are rare (mostly for testing to make sure you can recover).
Related
As we know Android would kill a paused Activity in some conditions. And there is a FIFO back stack of Activities.
My questions are as follows:
How Android kills an Activity without pulling it from the back stack (it might affect the top active Activity)
After killing it, what things are released from this Activity? And can I still get this Activity's instance?
Android does not kill Activities "separately", it kills the whole app process with all Activities.
The only way to get an Activity killed by the system is to set Don't keep Activities flag in device's Developer Options. However this option is just for development, not for applications in release.
Activity can't be killed but Os can kill the whole application. In this case you can try finish()/finishActivity()/context.finish() to finish the activity. While you finish an activity backpress will not return to the previous activity.
System can't kill activity, it can call the whole app.
And when it kills the whole app, it doesn't call any method from activity (onStop(), onDestroy(), etc)
Finally, you can't get activity instance.
I have got some programs, need help.
I switch my app(have activity) to background(eg:By Home-Key), and use other APP to kill it.
then check it by Using getRunningTasks() and getRunningAppProcesses(), but i can not understand the result : I can find the app's Activity（TopActivty/BaseActivity）in the RunningTasks, but not in RunningAppProcesses
My problems:
1、Home can i remove all Activity when the process been killed?
2、In this case, how can i restart my APP when click the app-icon?
Thanks
can i remove all Activity when the process been killed?
When your process goes away, your activities, services, threads, and all that go away as well.
However, the "task" remains. This is basically a description of the back stack for your app, and any apps launched from it that were launched into your task versus starting a fresh back stack in another task. This description includes things like your saved instance state (i.e., onSaveInstanceState() Bundle), the Intent that was used to start the activity, etc.
how can i restart my APP when click the app-icon?
If the user is returning to your app via the recent-tasks list, ideally you do not "restart" the app, but return the user to where the user left off.
The developer documentation covers various ways that you can control, somewhat, the behavior of the back stack and your app (or individual activities) as they come back into being when the user returns to one of your tasks.
Is there API or commands to force Android system to recycle all background activities no matter there is enough resource or not? And how to check all the activities' status to check that the activity is actually killed?
There is an API called killBackgroundProcesses(), but this API is killed the whole process, I am wondering how to only kill some activities without killing the whole process.
As the android dev guide page says below, I am looking for the first way.
activity lifecycle
If an activity is paused or stopped, the system can drop the activity
from memory by either asking it to finish, or simply killing its
process.
Yes, there is a way:
Settings -> Developer options -> Apps -> Don't keep activities
Check that box, and you are good to go.
Cheers.
I don't think so Android gives you the information of Activities are in background (i.e in Paused or Stopped State). Even if Activity Stack as well will give you the access of activity at Top.
Possible Solutions :
1. If at all you want to destroy the service , better to call finish() after startActivity() method.
2. If you want to periodically destroy all the background activities. You should implement your own activity stack. Which does pushToStack() on start of new activity and popFromStack() and then activity.finish();
Well apparently my android application doesnt close when I finish the activity so it there a way to force close it including any activity in my app that could be opened?
The fact that the process is still alive does not mean that the Activities did not finish. The process might be kept for a while until the OS decides to kill it.
If you have activities that do not finish properly, make sure that you did not leave a thread running.
There is no method in the API to close an Application. It is up to the OS to terminate it when it is convenient. The last resource is to kill the process, but you should never need to use that in your apps.
Make sure that threads that you have started terminate, and then invoke finish
Btw. How have you verified that you activity isn't closing?
Call finish() at the point when you want it to close. For example in onPause() if you want it to finish when the activity is no longer the topmost one.
I personally suggest you simply make sure your app does not do anything when it is not active and let the system worry about 'finishing' it.
i am working on an application that send and get data from internet each 5 min
if i press home key and my app goes to background... it will still continue sending/getting data from internet? or i have to do something special?
thanks
"If an activity is completely obscured by another activity, it is stopped. It still retains all state and member information, however, it is no longer visible to the user so its window is hidden and it will often be killed by the system when memory is needed elsewhere. If an activity is paused or stopped, the system can drop the activity from memory by either asking it to finish, or simply killing its process. When it is displayed again to the user, it must be completely restarted and restored to its previous state."
http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle
No. Activities shouldn't be depended on to process tasks in the background.
The following link illustrates the fundamentals of different Android components and what they do, i.e. the "parts" of an app.
You should be using a Service for background processing.
From what you're saying, I'd suggest an IntentService fired by an Alarm.
Application Fundamentals