Android Activity Lifecycle

 

What is the Android Lifecycle?

The Android Activity Lifecycle defines how an activity behaves in different states:
- Created
- Started
- Resumed
- Paused
- Stopped
- Destroyed

Lifecycle Methods

• onCreate(): Initialize your activity
• onStart(): Activity is about to become visible
• onResume(): Activity has become visible
• onPause(): Partially obscured
• onStop(): Fully obscured
• onRestart(): Restarting after stop
• onDestroy(): Cleanup before destruction



JAVA CODE

  1.   @Override  
  2.     protected void onCreate(Bundle savedInstanceState) {  
  3.         super.onCreate(savedInstanceState);  
  4.         setContentView(R.layout.activity_main);  
  5.         Log.d("lifecycle","onCreate invoked");  
  6.     }  
  7.     @Override  
  8.     protected void onStart() {  
  9.         super.onStart();  
  10.         Log.d("lifecycle","onStart invoked");  
  11.     }  
  12.     @Override  
  13.     protected void onResume() {  
  14.         super.onResume();  
  15.         Log.d("lifecycle","onResume invoked");  
  16.     }  
  17.     @Override  
  18.     protected void onPause() {  
  19.         super.onPause();  
  20.         Log.d("lifecycle","onPause invoked");  
  21.     }  
  22.     @Override  
  23.     protected void onStop() {  
  24.         super.onStop();  
  25.         Log.d("lifecycle","onStop invoked");  
  26.     }  
  27.     @Override  
  28.     protected void onRestart() {  
  29.         super.onRestart();  
  30.         Log.d("lifecycle","onRestart invoked");  
  31.     }  
  32.     @Override  
  33.     protected void onDestroy() {  
  34.         super.onDestroy();  
  35.         Log.d("lifecycle","onDestroy invoked");  
  36.     }  
  37. }  

  1. KOTLIN



  3. class MainActivity : Activity() {

  5.     override fun onCreate(savedInstanceState: Bundle?) {
  6.         super.onCreate(savedInstanceState)
  7.         setContentView(R.layout.activity_main)
  8.         Log.d("lifecycle", "onCreate invoked")
  9.     }

  11.     override fun onStart() {
  12.         super.onStart()
  13.         Log.d("lifecycle", "onStart invoked")
  14.     }

  16.     override fun onResume() {
  17.         super.onResume()
  18.         Log.d("lifecycle", "onResume invoked")
  19.     }

  21.     override fun onPause() {
  22.         super.onPause()
  23.         Log.d("lifecycle", "onPause invoked")
  24.     }

  26.     override fun onStop() {
  27.         super.onStop()
  28.         Log.d("lifecycle", "onStop invoked")
  29.     }

  31.     override fun onRestart() {
  32.         super.onRestart()
  33.         Log.d("lifecycle", "onRestart invoked")
  34.     }

  36.     override fun onDestroy() {
  37.         super.onDestroy()
  38.         Log.d("lifecycle", "onDestroy invoked")
  39.     }
  40. }




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