Instance Method

addObserver:forKeyPath:options:context:

Raises an exception.

Declaration

- (void)addObserver:(NSObject *)observer forKeyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options context:(void *)context;

Parameters

observer

The object to register for KVO notifications.

keyPath

The key path, relative to the array, of the property to observe. This value must not be nil.

options

A combination of NSKeyValueObservingOptions values that specifies what is included in observation notifications.

context

Arbitrary data that is passed to observer in observeValueForKeyPath:ofObject:change:context:.

Discussion

NSOrderedSet objects are not observable, so this method raises an exception when invoked on an NSOrderedSet object. Instead of observing an ordered set, observe the to-many relationship for which the ordered set is the collection of related objects.

See Also

Key-Value Observing Support

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

Learn more about using Apple's beta software