Represents a single focused thing the user can do.
In Android, you can override methods from the Activity to capture lifecycle methods for the activity itself, or register ActivityLifecycleCallbacks on the Application.
In Flutter, you have neither concept, but you can instead listen to lifecycle events by hooking into the WidgetsBinding observer and listening to the didChangeAppLifecycleState() change event.
An example of how to observe the lifecycle status of the containing activity:.
The observable lifecycle events are:.