通知
//获取通知中心单例对象
NSNotificationCenter * center = [NSNotificationCenter defaultCenter];
//添加当前类对象为一个观察者，name和object设置为nil，表示接收一切通知
[center addObserver:self selector:@selector(notice:) name:@"123" object:nil];
//创建一个消息对象
NSNotification * notice = [NSNotification notificationWithName:@"123" object:nil userInfo:@{@"1":@"123"}];
//发送消息
[[NSNotificationCenter defaultCenter]postNotification:notice];
-(void)notice:(id)sender{
NSLog(@"%@",sender);
}
