Android Activities Overview

Each screen your user interacts with is typically represented by an activity.

Every activity contains the layout, which has a user interface to interact with the user.

onCreate

<p>when activity is becoming visible to the user</p> Signup and view all the answers

<p>onPause</p> Signup and view all the answers

<p>onDestroy</p> Signup and view all the answers

<p>To launch a new activity or get an existing activity to perform an action</p> Signup and view all the answers

<p>Implicit Intent provides a generic action and can be handled by any app that matches the criteria, while Explicit Intent fulfills a request using a specific component</p> Signup and view all the answers

<p>To deliver a message to broadcast receivers</p> Signup and view all the answers

<p>To facilitate an application to run in the background to perform long-running operation tasks</p> Signup and view all the answers

<p>Intent intent=new Intent(Intent.ACTION_VIEW); intent.setData(Uri.parse(&quot;<a href="https://www.geeksforgeeks.org/">https://www.geeksforgeeks.org/</a>&quot;)); startActivity(intent);</p> Signup and view all the answers

<p>Intent i = new Intent(getApplicationContext(), ActivityTwo.class); startActivity(i);</p> Signup and view all the answers

<p>To ensure that the application remains active in the background so that the user can operate multiple applications at the same time.</p> Signup and view all the answers

<p>Foreground Services</p> Signup and view all the answers

<p>By calling stopService() method or the service can stop itself by using stopSelf() method.</p> Signup and view all the answers

<p>An application component binds itself with a service by calling bindService() method.</p> Signup and view all the answers

<p>All the components must unbind themselves from the service by using unbindService() method.</p> Signup and view all the answers

<p>Background Services</p> Signup and view all the answers

<p>Passing data from one activity to another</p> Signup and view all the answers

<p>All types of values (int, String, boolean, char)</p> Signup and view all the answers

<p>Using getIntent().getExtras() and getString(key, default_value)</p> Signup and view all the answers

<p>Viewing details of a single item, creating a new item, showing settings, and accessing services in other apps</p> Signup and view all the answers

<p>A messaging object that passes between components</p> Signup and view all the answers

<p>Using Intent.putExtras(Bundle)</p> Signup and view all the answers

<p>You should perform app startup logic and inflate the UI in the onCreate() method.</p> Signup and view all the answers

<p>The onResume() method allows the activity to gain input focus, enabling the user to interact with the activity. The activity remains in the resumed state until the system triggers it to be paused. Its counterpart is the onPause() method.</p> Signup and view all the answers

<p>The onStop() method is called when the activity is no longer visible to the user, and resources that aren't needed anymore should be released. Additionally, any persistent state that the user is in the process of editing should be saved to prevent loss of work.</p> Signup and view all the answers

<p>The onDestroy() method is called when the activity is about to be destroyed, which can be caused by the activity finishing or being dismissed by the user, or a configuration change. Final cleanup of resources should be performed, but do not rely on this method to save user data - save it earlier instead.</p> Signup and view all the answers

<p>To save and restore UI state in response to lifecycle changes, use the Bundle provided by the onSaveInstanceState() method. The onCreate() method receives the Bundle as an argument when the activity is created again.</p> Signup and view all the answers

<p>In the onSaveInstanceState() method, important UI state information should be stored in a Bundle that is used to recreate the activity if it is destroyed due to a configuration change or is terminated while in the background. This ensures that the user's work is retained and the UI state is consistent across changes.</p> Signup and view all the answers