Instance Method

addObserver(_:toObjectsAt:forKeyPath:options:context:)

Registers an observer to receive key value observer notifications for the specified key-path relative to the objects at the indexes.

Declaration

func addObserver(_ observer: NSObject, toObjectsAt indexes: IndexSet, forKeyPath keyPath: String, options: NSKeyValueObservingOptions = [], context: UnsafeMutableRawPointer?)

Parameters

anObserver

The observer.

indexes

The index set.

keyPath

The key path, relative to the array, to be observed.

options

The options to be included in the notification.

context

The context passed to the notifications.

Discussion

The options determine what is included in the notifications, and the context is passed in the notifications.

This is not merely a convenience method; invoking this method is potentially much faster than repeatedly invoking addObserver(_:forKeyPath:options:context:).