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.
Where is onSaveInstanceState called?
Note: onSaveInstanceState gets called
whenever you press the home button in your application as well
. Another note: Things like EditText can save and restore their content implicitly provided you’ve set an id on the View.
What is the use of 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.
Is onSaveInstanceState always called?
onSaveInstanceState() gets called regardless of whether or not your app process is killed.
What is the use of savedInstanceState in Android?
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.
What is a ViewModel Android?
Application context aware ViewModel . ViewModel is
a class that is responsible for preparing and managing the data for an Activity or a Fragment
. It also handles the communication of the Activity / Fragment with the rest of the application (e.g. calling the business logic classes).
How do you test OnRestoreInstanceState?
To test onSaveInstanceState and onRestoreInstanceState you can use either
the SetAlwaysFinish tool
(see link below) or the DevTools app included with the emulator. Both of these apps use a hidden setting called AlwaysFinish which is part of the ActivityManagerNative class to change the behavior of the Android OS.
Is OnRestoreInstanceState called after onCreate?
OnRestoreInstanceState(Bundle)
This method is called after OnStart() when
the activity is being re-initialized from a previously
saved state, given here in savedInstanceState .
Is onDestroy always called?
Android Activity onDestroy
() is not always called
and if called only part of the code is executed. onDestroy() is not always called. If called, only part of the code is executed.
Is onResume called after onCreate?
onResume()
will never be called before onCreate
() . onResume() will always be called when the activity goes into foreground, but it will never be executed before onCreate() .
Why is savedInstanceState null?
If there is no available instance data
, the savedInstanceState will be null . For example, the savedInstanceState will always be null the first time an Activity is started, but may be non-null if an Activity is destroyed during rotation. … For example, here’s how you can restore some state data in onCreate() .
What’s the difference between activity onCreate () and onStart ()?
onCreate() is called
when the when the activity is first created
. onStart() is called when the activity is becoming visible to the user.
What is Android application life cycle?
| Activity Lifecycle Methods | onCreate() Called when activity first created No | onRestart() Called after activity stopped, prior to restarting No | onStart() Called when activity is becoming visible to user No | onResume() Called when activity starts interacting with user No |
|---|
What is the use of SetContentView in Android?
SetContentView is used
to fill the window with the UI provided from
layout file incase of setContentView(R. layout. somae_file). Here layoutfile is inflated to view and added to the Activity context(Window).
What does the onCreate do in Android?
onCreate(Bundle savedInstanceState) Function in Android:
After Orientation changed then onCreate(Bundle savedInstanceState)
will call and recreate the activity and load all data from savedInstanceState
. Basically Bundle class is used to stored the data of activity whenever above condition occur in app.
What is the use of Appcompatactivity in Android?
Base class
for activities that wish to
use some of the newer platform features on older Android devices. Some of these backported features include: Using the action bar, including action items, navigation modes and more with the setSupportActionBar(Toolbar) API.
