How can I do some cleanup right before an Android app is quitting?

Question

Is there some sort of onTerminate() method where I can do some cleanup (I want to clear some SharedPreferences) when my Android app is terminating?

I have an Activity that is keeping a running average of a few numbers, that I'm storing in a SharedPreference. I want this average to last while the app is running (the user can move between different activities) so I can't clear it on onDestroy() for that particular activity. I need to be able to clear it once the app is about to quit.

How can I do this?

Answer 1

I've not tried this, but here's what I would do:

• As Alex mentioned in the comment to original question, use a Service to share the app-wide state between Activities.
• Whenever you move between Activities, bind to the service from the "new" activity, and unbind from the "old" one. Check this to understand how to coordinate activities.
• If you follow this properly, you can ensure that at least one Activity is always bound to the Service as long as your app is running; and that all Activities are unbound when the app is no longer running - at which point your service's onDestroy() is called. This is where you perform your cleanup.