The method onSaveInstanceState() isn’t called when an Activity finishes naturally like on a back button press. That’s your app itself destroying the Activity . The method is only called if the Android OS anticipates that it may have to kill your activity to reclaim resources.
When onSaveInstanceState is called?
onSaveInstanceState method gets called typically before/after onStop() is called. This varies from Android version to version. In the older versions it used to get before onStop() . Inside this method, we save the important values in the Bundle in the form of key value pairs.
What is onSaveInstanceState()?
The onSaveInstanceState() method allows you to add key/value pairs to the outState of the app. Then the onRestoreInstanceState() method will allow you to retrieve the value and set it back to the variable from which it was originally collected.
How can I maintain fragment state when added to the back stack?
Solution: Save required information as an instance variable in calling activity. Then pass that instance variable into your fragment. So following on with my example: before I display F2 I save user data in the instance variable using a callback.
Can not perform this action after onSaveInstanceState in Android?
Short And working Solution : Step 1 : Override onSaveInstanceState state in respective fragment. And remove super method from it. Step 2 : Use fragmentTransaction. commitAllowingStateLoss( );
When in the activity lifecycle is onSaveInstanceState () called?
Saving Activity instance state To save information to the instance state Bundle , use the onSaveInstanceState() callback. This is not a lifecycle callback method, but it is called when the user is leaving your Activity (sometime before the onStop() method).
What is the fragment lifecycle in Android?
Each Fragment instance has its own lifecycle. When a user navigates and interacts with your app, your fragments transition through various states in their lifecycle as they are added, removed, and enter or exit the screen.
How can we prevent fragment recreation in navigation component?
1 Answer. When I press the back button from C, I want it to just go back to B then A without recreating fragments that are already in the back stack. When you are navigating to a destination, you can pop the old instance of the destination from the back stack. Just add the pop inclusive to all your action in nav graph.
How do I recreate fragments?
Re-attach a fragment after it had previously been deatched from the UI with detach(Fragment). This causes its view hierarchy to be re-created, attached to the UI, and displayed. Detach the given fragment from the UI.
What is commitAllowingStateLoss?
The fragment transaction is lost in this case — Android will restore your application state, activities and fragments, but it has no track of your Fragment transaction. Some other apps “re-initialise” the state of the activity after a process kill, in that case using commitAllowingStateLoss() will also do no harm.
Which method is called only once in a fragment life cycle?
3 Answers. onCreate and onDestroy id fired only once.
What does onrestoreinstancestate() method does in a fragment?
It means that every single member variables are also destroyed. You have to manually save and restore those variables through onSaveInstanceState and onActivityCreated method respectively. Note that there is no onRestoreInstanceState method inside Fragment.
Why is savedinstancestate null when restoring a fragment?
When an Activity is created, you can rely on savedInstanceState being null if it is a new Activity and having saved state if it is being restored. Fragments don’t seem to enjoy the same luxury at times. When the framework calls onCreate or onCreateView you might not have saved state even if the Fragment is being restored!
When does a fragment save its state?
There are many situations where a fragment may be mostly torn down (such as when placed on the back stack with no UI showing), but its state will not be saved until its owning activity actually needs to save its state. In other words, Fragments will only save their state when their containing Activity saves its state.
What is onsaveinstancestate method in Salesforce?
In the Bundle you can save user selections (for example, tab), scroll view positions, user-submitted data (for example, any form data). onSaveInstanceState method is the moment where you can save values you want be restored when activity will be recreated after a pause.
