How do you save a fragment state in 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!
What is saving state in 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.
How do I save my savedInstanceState data?
In order to save sates of UI, I override onSaveInstanceState(Bundle savedInstanceState) and save all the data of the UI in savedInstanceState Bundle. This method is called before onStop() in older versions of Android (till android 8.0) and can be called after onStop() for newer versions. super.
How do I use savedInstanceState Kotlin?
- Create a new project “Build Your First Android App in Kotlin“
- Add following code in “activity_main. xml“
- Open the “MainActivity.kt” and add the following code.
- Now Run the application, in an emulator or on your Android device.
- Download source code onSaveInstanceState in kotlin.
How do I save a fragment?
- In a Fragment, there are UI view objects and instance variables. For the UI view objects which has id, android OS will save their view instance state data automatically.
- But for those Fragment instance variables, you need to save the value in the Bundle in onSaveInstanceState(Bundle outState) method.
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.
How can I get fragments to run faster?
You can use Async Task to perform the time-consuming tasks and take them off the UI thread. This will allow the fragment to load quickly and the list to populate “lazily”.
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.
How do you restore the state of an Android activity?
State can be restored in either the onCreate() or the onRestoreInstanceState() methods of the activity by extracting values from the Bundle object and updating the activity based on the stored values.
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.
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.
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.
Why is my Android fragment state not saving?
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.
How to save the state of a fragment?
In order to save the Fragment state you need to implement onSaveInstanceState () : “Also like an activity, you can retain the state of a fragment using a Bundle, in case the activity’s process is killed and you need to restore the fragment state when the activity is recreated.
What are the state types mentioned in the fragment state table?
The state types mentioned in the table are as follows: Variables: local variables in the fragment. View State: any data that is owned by one or more views in the fragment. SavedState: data inherent to this fragment instance that should be saved in onSaveInstanceState ().
What are the advantages and disadvantages of using Android fragments?
Android fragment has some advantages and some disadvantages. The most disadvantage of the fragment is that when you want to use a fragment you create it ones. When you use it, onCreateView of the fragment is called for each time.