Type Alias

NSKeyValueChangeKey

The keys that can appear in the change dictionary.

Declaration

typedef NSString *NSKeyValueChangeKey;

Discussion

These constants are used as keys in the change dictionary passed to observeValueForKeyPath:ofObject:change:context:.

Topics

Type Properties

NSKeyValueChangeIndexesKey

If the value of the NSKeyValueChangeKindKey entry is NSKeyValueChangeInsertion, NSKeyValueChangeRemoval, or NSKeyValueChangeReplacement, the value of this key is an NSIndexSet object that contains the indexes of the inserted, removed, or replaced objects.

NSKeyValueChangeKindKey

An NSNumber object that contains a value corresponding to one of the NSKeyValueChange enums, indicating what sort of change has occurred.

NSKeyValueChangeNewKey

If the value of the NSKeyValueChangeKindKey entry is NSKeyValueChangeSetting, and NSKeyValueObservingOptionNew was specified when the observer was registered, the value of this key is the new value for the attribute.

NSKeyValueChangeNotificationIsPriorKey

If the NSKeyValueObservingOptionPrior option was specified when the observer was registered this notification is sent prior to a change.

NSKeyValueChangeOldKey

If the value of the NSKeyValueChangeKindKey entry is NSKeyValueChangeSetting, and NSKeyValueObservingOptionOld was specified when the observer was registered, the value of this key is the value before the attribute was changed.