Android Activity Lifecycle is controlled by 7 methods of android.app.Activity class. The android Activity is the subclass of ContextThemeWrapper class. An activity is the single screen in android. It is like window or frame of Java. By the help of activity, you can place all your UI components or widgets in a single screen. The 7 lifecycle method of Activity describes how activity will behave at different states.
Following are the seven lifecycle methods of android activity:
Method |
Description |
onCreate() |
Called when the activity will start interacting with the user. At this point your activity is at the top of the activity stack, with user input going to it.,Always followed by onPause(). |
onRestart() |
Called after your activity has been stopped, prior to it being started again.,Always followed by onStart() |
onStart() |
Called when the activity is becoming visible to the user.,Followed by onResume() if the activity comes to the foreground, or onStop() if it becomes hidden. |
onResume() |
Called when the activity will start interacting with the user. At this point your activity is at the top of the activity stack, with user input going to it.,Always followed by onPause(). |
onPause() |
Called when the system is about to start resuming a previous activity. This is typically used to commit unsaved changes to persistent data, stop animations and other things that may be consuming CPU, etc. Implementations of this method must be very quick because the next activity will not be resumed until this method returns.,Followed by either onResume() if the activity returns back to the front, or onStop() if it becomes invisible to the user. |
onStop() |
Called when the activity is no longer visible to the user, because another activity has been resumed and is covering this one. This may happen either because a new activity is being started, an existing one is being brought in front of this one, or this one is being destroyed.,Followed by either onRestart() if this activity is coming back to interact with the user, or onDestroy() if this activity is going away. |
onDestroy() |
The final call you receive before your activity is destroyed. This can happen either because the activity is finishing (someone called finish() on it, or because the system is temporarily destroying this instance of the activity to save space. You can distinguish between these two scenarios with the isFinishing() method. |