Android Lifecycle
Activity/Fragment Lifecycle, Configuration Changes and state management
1What is the correct lifecycle order of an Activity when starting?
What is the correct lifecycle order of an Activity when starting?
回答
An Activity's lifecycle starts with onCreate() (initialization and view creation), followed by onStart() (Activity becomes visible but not yet interactive), then onResume() (Activity in foreground and interactive). This sequence is always the same for each Activity start.
2Which first lifecycle method is called when the Activity goes to background?
Which first lifecycle method is called when the Activity goes to background?
回答
onPause() is the first method called when the Activity starts losing focus. It's followed by onStop() when the Activity is no longer visible at all. Critical data should be saved in onPause() as the system may kill the process after this method without calling onStop().
3In which method should you initialize Views (findViewById, ViewBinding)?
In which method should you initialize Views (findViewById, ViewBinding)?
回答
onCreate() is the appropriate method to initialize Views as this is where setContentView() is called and the View hierarchy is created. Views are not yet available before onCreate(). You can also use onViewCreated() in Fragments.
What is the difference between onPause() and onStop()?
What happens during screen rotation by default?
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