注册通知
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];