Block回调

•Block的定义

 

•Block、委托、通知、回调函数，它们虽然名字不一样，但是原理都一样，都是“回调机制”的思想的具体实现

•前面的代理模式的项目改为Block回调实现

  

Block回调案例 1

 

•typedef long(^LookforApartme)(Person *person);

•

•@property(nonatomic)LookforApartme lookforApartme;

•

•long price=_lookforApartme(self);

•

•Person *person=[[Person alloc] init];

•   

•[person lookforApartmeBlock:^long(Person *person) {

•        long price = random()%10 * 1000;       

•        NSLog(@"正在努力的找房子，找到一个价格为%ld的房子",price);

•        return price;

• }];

•

Block回调案例2

•typedef void (^WashBlock)(Children *children);

•typedef void (^PlayBlock)(Children *children);

•

•@property(nonatomic)WashBlock washBlock;

•@property(nonatomic)PlayBlock playBlock;

•

• self.washBlock(self);

• self.playBlock(self);

 

KVO，代理，Block回调的区别

 

•KVO：可以是一对一或者一对多

•代理：只能是一对一

•Block回调块：代码以闭包得形式将各种内容进行传递