问题
I use my Android app's application Context as a storage area for "current state" information for my app.
I'm finding that in the field, there are cases when this information goes away on some people's devices causing various NullPointerExceptions since I expect the data to be there when the app resumes and starts rebuilding the necessary activities.
This usually happens when the user hits "Home", does something else, then eventually wanders back into the app - it attempts to go back to where it was before, but the application Context has mysteriously lost all its previously-saved state information (in my case, a few integers and a few Strings).
I know this is a very vague question, but are there any cases (other than the user using "back" to back completely out of the application) where the application Context gets completely destroyed even though the application is not terminated?
Is there a better way to maintain persistent state information?
回答1:
Yes, it is possible for the Application to be killed and restarted if the user leaves the application for a while. You might want to read this section on processes and lifecycles.
You should find an appropriate place to save state to a persistent store. If its just a few integers and strings, it should be pretty simple to save them to shared preferences as they change. See data storage - shared preferences.
来源：https://stackoverflow.com/questions/4136154/does-the-android-application-context-ever-get-destroyed