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When user click on a notification, I set up a backstack of Activities A -> B, where B is on top and shown to user. I would like the lifecycles of Activity A to run, so that when user presses back button and comes to Activity A, it is already ready. What could I do to achieve this?

hch
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    I cannot see that is possible, because the way that system gives us ability to launch a stack of activities is `TaskStackBuilder` and that won't make all of the activities on the stack to reach their `onResume()`, because obviously those activities have not yet been displayed to user, only the topmost activity will reach `onResume` state. As soon as you navigate back to previous activity - only then the activity will be created and reach `onResume` state. I think you should reconsider your app logics. What use-case you have? – azizbekian Aug 08 '19 at 06:56
  • Can you give some concrete examples of what you want to preload? – charles-allen Aug 11 '19 at 08:31
  • seems like a resource intensive app? – danny117 Aug 13 '19 at 13:54

2 Answers2

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This cannot be possible as android will not allow us to do that, the only way I can see you can achieve this by doing your Activity A operation inside your Activity B And provide those details to Activity A when the user pressed back button.

Note: If you are showing any kind of list on Activity A or doing similar kind of work, you can have one Singleton Class where you can get your data in Activity B which required by Activity A, and provide same data to Activity A when the user pressed back button.

Jitesh Mohite
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You should open the activity as normal but then put this line of code in the OnCreate() method to bring to the back.

moveTaskToBack(true);
Abdulrahman Abdelkader
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