[Swift] addObserver를 한 뒤 remove를 해주어야 하는가?

 

https://developer.apple.com/documentation/foundation/notificationcenter/1413994-removeobserver

위 문서에 따르면 iOS9.0 이후에는 observer를 unregister하지 않아도 된다고 한다.

If your app targets iOS 9.0 and later or macOS 10.11 and later, and you used [addObserver(_:selector:name:object:)], you do not need to unregister the observer. If you forget or are unable to remove the observer, the system cleans up the next time it would have posted to it.

 

하지만 block기반으로 observer를 등록했다면 명시적으로 unregister해주어야 한다고 한다.

If you used [addObserver(forName:object:queue:using:)] to create your observer, you should call this method or [removeObserver(_:name:object:)] before the system deallocates any object that [addObserver(forName:object:queue:using:)] specifies.

 

이것을 코드로 실험해본 포스트가 아래와 같다.

https://oleb.net/blog/2018/01/notificationcenter-removeobserver/

Do you have to manually unregister block-based NotificationCenter observers? – Ole Begemann