removeObserver(_:forKeyPath:)
Stops the observer object from receiving change notifications for the property specified by the key path relative to the object receiving this message.
Declaration
func removeObserver(_ observer: NSObject, forKeyPath keyPath: String)Parameters
- observer:
The object to remove as an observer.
- keyPath:
A key-path, relative to the object receiving this message, for which
observeris registered to receive KVO change notifications.
Discussion
It is an error to call removeObserver(_:forKeyPath:) for an object that has not previously been registered as an observer.
Be sure to invoke this method (or removeObserver(_:forKeyPath:context:)) before any object specified in addObserver(_:forKeyPath:options:context:) is deallocated.