Instance Method


Tells the delegate when the app is about to terminate.


optional func applicationWillTerminate(_ application: UIApplication)



Your singleton app object.


This method lets your app know that it is about to be terminated and purged from memory entirely. You should use this method to perform any final clean-up tasks for your app, such as freeing shared resources, saving user data, and invalidating timers. Your implementation of this method has approximately five seconds to perform any tasks and return. If the method does not return before time expires, the system may kill the process altogether.

For apps that do not support background execution or are linked against iOS 3.x or earlier, this method is always called when the user quits the app. For apps that support background execution, this method is generally not called when the user quits the app because the app simply moves to the background in that case. However, this method may be called in situations where the app is running in the background (not suspended) and the system needs to terminate it for some reason.

After calling this method, the app also posts a UIApplicationWillTerminate notification to give interested objects a chance to respond to the transition.

See Also

Related Symbols

func applicationDidEnterBackground(UIApplication)

Tells the delegate that the app is now in the background.

func application(UIApplication, didFinishLaunchingWithOptions: [UIApplicationLaunchOptionsKey : Any]? = nil)

Tells the delegate that the launch process is almost done and the app is almost ready to run.