Activity Life Cycle

Activity Life-Cycle method –

1.    onCreate(Bundle savedInstanceState) : Called when the activity is starting.

2.    onStart() : Called after onCreate(Bundle) — or after onRestart() when the activity had been stopped, but is now again being displayed to the user.

3.    onResume() :  Called after onRestoreInstanceState(Bundle), onRestart(), or onPause(), for your activity to start interacting with the user.

4.    onPause() : Called as part of the activity lifecycle when an activity is going into the background, but has not (yet) been killed.

5.    onStop() : Called when you are no longer visible.

6.    onRestart() : Called after onStop() when the current activity is being re-displayed to the user (the user has navigated back to it).

7.    onDestroy() : Perform any final cleanup before an activity is destroyed.

More Depth

Situations

1.    When open the app

onCreate() --> onStart() -->  onResume()

2.    When back button pressed and exit the app

onPaused() -- > onStop() --> onDestory()

3.    When home button pressed

onPaused() --> onStop()

4.    After pressed home button when again open app from recent task list or clicked on icon

onRestart() --> onStart() --> onResume()

5.    When open app another app from notification bar or open settings

onPaused() --> onStop()

6.    Back button pressed from another app or settings then used can see our app

onRestart() --> onStart() --> onResume()

7.    When any dialog open on screen

onPause()

8.    After dismiss the dialog or back button from dialog

onResume()

9.    Any phone is ringing and user in the app

onPause() --> onResume()

10. When user pressed phone's answer button

onPause()

11. After call end

onResume()

12. When phone screen off

onPaused() --> onStop()

13. When screen is turned back on

onRestart() --> onStart() --> onResume()

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Case :  First Activity - Second Activity

1. When first Activity open

 In the First onCreate() event
 In the First onStart() event
 In the First onResume() event

2. When called First to Second Activity

In the First onPause() event
In the Second onCreate() event
In the Second onStart() event
In the Second onResume() event
In the First onStop() event

3. When called Second to First Activity

In the Second onPause() event
In the First onCreate() event
In the First onStart() event
In the First onResume() event
In the Second onStop() event

Note - 2, 3 are common

4. When pressed home button, app running in background

In the First onPause() event
In the First onStop() event

5. When removed from background 


In the First onDestroy() event

Case 2 : When called all method

First onCreate() event
First onStart() event
First onPostCreate() event
First onResume() event

First onPostResume() event

Below Image for Deep understanding