What is saved state android?
The saveState() method allows your component to return a Bundle containing any state that should be saved from that component. SavedStateRegistry calls this method during the saving state phase of the UI controller’s lifecycle. Kotlin Java.
How do you save the state of fragment Kotlin?
The first key is that we can save our Fragments’ state ourselves using FragmentManager. saveInstanceState(Fragment) . Before removing the Fragment, call this method to get a Bundle containing your Fragment’s saved state!
How do I use onSaveInstanceState and onRestoreInstanceState on Android?
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.
What is retained fragment Android?
A Fragment represents a reusable portion of your app’s User Interface. Retained Fragment consists of the configuration change that causes the underlying Activity to be destroyed. The term “retained” refers to the fragment that will not be destroyed on configuration changes.
What is ViewModelProvider factory?
The factory is responsible to create your instance of ViewModel. If your ViewModel has dependencies and you want to test your ViewModel then you should create your own ViewModelProvider. Factory and passed dependency through ViewModel constructor and give value to the ViewModelProvider.
How do you save the current state of the fragment?
Various Android system operations can affect the state of your fragment. To ensure the user’s state is saved, the Android framework automatically saves and restores the fragments and the back stack. Therefore, you need to ensure that any data in your fragment is saved and restored as well.
How do I keep fragments alive?
If you want to keep your fragment running you can instead use FragmentManger hide() and show() methods! It hides and shows the fragments without destroying them. so first add both fragments to fragment manager and also hide the second fragment.
How would you preserve activity state during a screen rotation?
4 Answers
- Assuming you have 2 XML layout files for portrait and landscape, put your main.xml layout file in the following folders: res/layout/main.xml <– this will be your portrait layout.
- Now to save your text from the text view =) Lets assume your textview is named as MyTextView in your layout xml file.
How do you save Onsaveinstancestate?
If thats the case you can save that in Bundle as long as your Card class correctly implements Parcelable Interface. Ok so make sure Card class implements Parcelable. You can look it up on google “android parcelable example” After Card correctly implements Parcelable you can pass the card instance in savedInstanceState.
What are fragment States?
Android Fragment is the part of activity, it is also known as sub-activity. There can be more than one fragment in an activity. Fragments represent multiple screen inside one activity. Android fragment lifecycle is affected by activity lifecycle because fragments are included in activity.
What is the purpose of an AndroidViewModel?
The AndroidViewModel class is a subclass of ViewModel and similar to them, they are designed to store and manage UI-related data are responsible to prepare & provide data for UI and automatically allow data to survive configuration change.
Why do we need ViewModelProvider?
Why we need ViewModel Factory? We are unable to create ViewModel on our own. To create ViewModels, we need the ViewModelProviders utility provided by Android. ViewModelProviders, on the other hand, can only instantiate ViewModels with no arg constructor.
What is the use of ViewModelProvider?
Creates ViewModelProvider , which will create ViewModels via the given Factory and retain them in the given store . ViewModelStore : ViewModelStore where ViewModels will be stored.
How do you save a state of fragment in BottomNavigationView?
BottomNavigationView + Save fragment states while navigating to different tabs
- Tab 1 – Gets data from a server and displays to RecyclerView.
- Tab 2 – Gets a URL from the server and loads Webview.
- Tab 3 – Gets data from the server and displays to RecyclerView.
- Tab 4 – Setting screen using PreferenceFragmentCompat.
What is saved instance?
The savedInstanceState is a reference to a Bundle object that is passed into the onCreate method of every Android Activity. Activities have the ability, under special circumstances, to restore themselves to a previous state using the data stored in this bundle.
How do you persist state information during changes in configuration?
If you want to persist the state of an activity so that it can be restored later, when the activity is recreated (when the device changes orientation), a much simpler way is to implement the onSaveInstance() method, as it provides a Bundle object as an argument so that you can use it to save your activity’s state.