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.
How do you use onCreate method?
How to use onCreate method in android. app. Fragment
- FragmentManager fragmentManager;String tag;fragmentManager.findFragmentByTag(tag)
- FragmentManager fragmentManager;fragmentManager.findFragmentById(id)
- Activity activity;String tag;activity.getFragmentManager().findFragmentByTag(tag)
What happens in onCreate?
onCreate(savedInstanceState); To make it simple it recreates the state of the app when you change orientation of device. When you start the app savedInstanceState is empty so nothing happens, but when you rotate a smartphone or tablet Android saves the state of activity to so called Bundle and then reload it.
What is called after onCreate Android?
onStart(): This method is called when an activity becomes visible to the user and is called after onCreate. … onPause(): It is called when the app is partially visible to the user on the mobile screen. onStop(): It is called when the activity is no longer visible to the user.
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 is Android application life cycle?
Overview of Android Lifecycles
| 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 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.
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.
How do I use onPause in Android?
How to use onPause method in android. app. Fragment
- FragmentManager fragmentManager;String tag;fragmentManager.findFragmentByTag(tag)
- FragmentManager fragmentManager;fragmentManager.findFragmentById(id)
- Activity activity;String tag;activity.getFragmentManager().findFragmentByTag(tag)
Is OnCreate only called once?
@OnCreate is only for initial creation, and thus should only be called once. If you have any processing you wish to complete multiple times you should put it elsewhere, perhaps in the @OnResume method.
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 .
What is onPause method?
onPause(): This method gets called when the UI is partially visible to the user. If a dialog is opened on the activity then the activity goes to pause state and calls onPause() method. Here the activity is in the paused state. onStop(): This method gets called when the UI is not visible to the user.
Is it possible activity without UI in Android?
The answer is yes it’s possible. Activities don’t have to have a UI. It’s mentioned in the documentation, e.g.: An activity is a single, focused thing that the user can do.