What is the savedInstanceState Bundle? 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 super onCreate savedInstanceState in Android?
By calling super. onCreate(savedInstanceState); , you tell the Dalvik VM to run your code in addition to the existing code in the onCreate() of the parent class. If you leave out this line, then only your code is run. The existing code is ignored completely.
What is the purpose of onCreate () function in Android?
onCreate(Bundle savedInstanceState) Function in Android:
Basically Bundle class is used to stored the data of activity whenever above condition occur in app. onCreate() is not required for apps. But the reason it is used in app is because that method is the best place to put initialization code.
What is onStart method in Android?
onStart(): This method is called when an activity becomes visible to the user and is called after onCreate. onResume(): It is called just before the user starts interacting with the application. … onDestroy(): It is called when the activity is cleared from the application stack.
What is an activity in Android?
An activity represents a single screen with a user interface just like window or frame of Java. Android activity is the subclass of ContextThemeWrapper class. If you have worked with C, C++ or Java programming language then you must have seen that your program starts from main() function.
What is onCreate () method?
onCreate is used to start an activity. super is used to call the parent class constructor. setContentView is used to set the xml.
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).
How do I use getIntent on Android?
you can retrieve this data using getIntent in the new activity: Intent intent = getIntent(); intent. getExtra(“someKey”) … So, it’s not for handling returning data from an Activity, like onActivityResult, but it’s for passing data to a new Activity.
What is Android application life cycle?
The Three Lives of Android
The Entire Lifetime: the period between the first call to onCreate() to a single final call to onDestroy(). We may think of this as the time between setting up the initial global state for the app in onCreate() and the release of all resources associated with the app in onDestroy().
What is a bundle in Android?
Android Bundle is used to pass data between activities. The values that are to be passed are mapped to String keys which are later used in the next activity to retrieve the values. Following are the major types that are passed/retrieved to/from a Bundle.
What is the use of onResume method in Android?
onResume() is one of the methods called throughout the activity lifecycle. onResume() is the counterpart to onPause() which is called anytime an activity is hidden from view, e.g. if you start a new activity that hides it. onResume() is called when the activity that was hidden comes back to view on the screen.
What is the difference between onCreate and onStart Android?
onCreate() is called when the when the activity is first created. onStart() is called when the activity is becoming visible to the user.
When onPause method is called in Android?
onPause. Called when the Activity is still partially visible, but the user is probably navigating away from your Activity entirely (in which case onStop will be called next). For example, when the user taps the Home button, the system calls onPause and onStop in quick succession on your Activity .
How do you kill an activity?
Launch your application, open some new Activity, do some work. Hit the Home button (application will be in the background, in stopped state). Kill the Application — easiest way is to just click the red “stop” button in Android Studio. Return back to your application (launch from Recent apps).
What is an activity?
An activity provides the window in which the app draws its UI. This window typically fills the screen, but may be smaller than the screen and float on top of other windows. Generally, one activity implements one screen in an app.
What is difference between activity and AppCompatActivity in Android?
Activity is the baseline. Every activity inherits from Activity , directly or indirectly. FragmentActivity is for use with the backport of fragments found in the support-v4 and support-v13 libraries. … AppCompatActivity is from the appcompat-v7 library.