What ViewController methods are called when minimizing and returning to the app?

When minimizing and returning to an app on iOS, the ViewController lifecycle methods related to the appearance and disappearance of the view are called:

• When minimizing (the app goes to the background):

  • viewWillDisappear(_:) — called before the ViewController is no longer visible.
  • viewDidDisappear(_:) — called after the ViewController is no longer visible.

• When returning (the app becomes active):

  • viewWillAppear(_:) — called before the ViewController becomes visible.
  • viewDidAppear(_:) — called after the ViewController becomes visible.

Additionally, you can track app transitions to the background and back through the notifications UIApplication.willResignActiveNotification and UIApplication.didBecomeActiveNotification.

Example:

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    // Save state or stop updates
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    // Update UI or resume processes
}