We analyzed the KVO principle in the KVO analysis (1) of the underlying principle of iOS above, and this paper mainly defines the implementation of KVO according to the KVO principle.
Define managementKVOInformation of the class
Define management KVO class information, mainly including the Observer, keyPath, NSKeyValueObservingOptions and monitored properties change callback block, for example, this paper takes SafeKVOInfoManager class for class management, the code is as follows
- .h code
- The m code
KVOProcessing classKey points and difficulties
To make our custom KVO available to all classes that inherit from NSObject, the KVO processing class handles the classification of NSObject. This paper uses NSObject+SafeKVO classification as the KVO processing class.
NSObject+SafeKVOClassification declaration function
safeAddObserver:Function analysis
We add attributes to any objectKVOListen, both need to be calledsafeAddObserver:function
judgeSetterMethodFromeKeyPathFunction analysis
setterForGetterfunction
There are also getters that get from setter methodsgetterForSetter
Derived functioncreatSafeKVONotifingObservingKVOWithKeyPathAnalysis of the
safe_classFunction analysis
safe_setterFunction analysis
safe_deallocAnalysis of the
safe_deallocAnalysis of results after operation
safeRemoveObserverFunction analysis
safeRemoveObserverFunctions can be called differently
