iOS Development _kvc&kvo

The 1.KVC approach is provided by the Nskeyvaluecoding protocol, and NSObject implements the protocol, meaning that almost all objects in OBJC support KVC operations.

2.setValue: Attribute value Forkeypath: attribute path, can simplify writing

3. To implement KVO in OBJC, the Nskeyvalueobserving protocol must be implemented, but fortunately NSObject has implemented the protocol, so almost all OBJC objects can use KVO

4.KVO is actually an observer pattern, which makes it easy to separate the view component from the data model, and when the data model's attribute value changes, the view component of the listener is fired, and the listener itself is invoked when fired

iOS Development _kvc&kvo