代码改变世界

KVO

2015-10-15 20:44  xiangjune  阅读(151)  评论(0编辑  收藏  举报

// ———————————————————————KVO——————————————

 

// 定义对象,设置KVO

p = [[Person alloc] init];

p.name = @"zhangsan";

p.age = 22;

[p addObserver:self forKeyPath:@"age" options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld context:NULL];

 

// 实现KVO监听

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context

{

    if([@"age" isEqualToString:keyPath])

    {

        NSLog(@"observeValueForKeyPath.....");

    }

}

 

// 释放

-(void)dealloc

{

    [p removeObserver:self forKeyPath:@"age"];

}