startActivityForResult有时会导致主活动结束并从活动堆栈中删除

Question

I have a main app A , use startActivityForResult to start app B .

Everything goes fine but recently sometimes app A has been finished and removed from the activity stack (without any error prompt).

App B is still running well without any problem.

After I check for the activity stack, app A was gone and app B is still there ( adb shell dumpsys activity command).

Anybody know how to solve this issue?

Answer 1

In the documentation of the onDestroy() method of Activity. It's said :

Perform any final cleanup before an activity is destroyed. This can happen either because the activity is finishing (someone called finish() on it, or because the system is temporarily destroying this instance of the activity to save space. You can distinguish between these two scenarios with the isFinishing() method.

The system could choose by itself to kill your activity A if it consider it needs more place. That's what append to you.

As said in the doc, you could avoid it by Override the OnDestroy() method and check if it's finishing by user call or by system call using isFinnishing() . Then you could for example call super.onDestroy() only if it's a user destroy and not a system one. Be careful this mean the system will never be able to kill your activity by itself so you have to make sure you call finnish()