I just did a little test: I started my app, went to a certain screen, pressed the home button and killed the process via Advanced Task Killer.
Now, if I go back to my app just a few moments later, I come back to that very screen. I also know that onRestoreInstanceState() is called in this case, as I have played around with this method quite a bit.
However, just out of curiosity, I did all the same, but let my phone lie around for some time (an hour or something). When I restarted my app, it went straight to the main activity.
So my question is: for how long does Android keep the saved state? or what determines if it throws it away or not? I already figured out it had nothing to do with lockscreen on/off.
Kind regards,
jellyfish
The activity is restored because such applications as Advanced Task Killer use “illegal” methods for killing applications. Android kills application is a similar way when it’s low on memory and when killed application is launched again its state is restored.
Android keeps an application state for some time. Usually it’s about 15-30 minutes but I think it depends on the device. But you can ask Android to keep an activity state “forever” (until the activity is finished) using android:alwaysRetainTaskState=”true” attribute.