when to use “willChangeValueForKey” and “didChangeValueForKey”?

Question

I saw these lines in a demo project, but I couldn\'t understand why it did that.

[self willChangeValueForKey:@\"names\"];
[self didChangeValueForKey:@\"names\"];         


        

Answer 1

if you rewrite property getter methods, please use it.

@property (assign, nonatomic, getter=isLogined) BOOL logined;