CODEWITHSUNDEEP
androidandroid-activitylifecycle
jellyfish
jellyfish

Reputation: 7988

For how long does Android save a killed activity's state?

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

Upvotes: 2

Views: 2003

Answers (3)

Michael
Michael

Reputation: 54705

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.

Upvotes: 2

DeeV
DeeV

Reputation: 36035

Android will dispose of the activity when it needs the resources that the activity is holding (usually memory) and the activity is not in the foreground. There's more criteria involved, but that's the general case. There's no predefined time limit or criteria other than "when it decides it needs to". The app could die almost immediately or it could stay up indefinitely. You should never assume your app will ever be killed and you should never assume your app will never be killed.

Upvotes: 0

Guillaume
Guillaume

Reputation: 9061

When you killed an application with Advanced Task Killer for example, the application restart with the main activity the next time. I suppose that the application save the state in file to restore the same activity even if it killed!

Upvotes: 0

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