Notifycation

1. 类A 抛出消息

 [[NSNotificationCenter defaultCenter] postNotificationName:@"USB_DISCONNECTED" object:str];

-(void)register{
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    
    // 2.通过异步函数将将任务加入队列
    dispatch_async(queue, ^{
        for(int i = 0 ;i <= 20; ++i){
        [NSThread sleepForTimeInterval:1];
            NSString * str = [NSString stringWithFormat:@"%d",i];
        [[NSNotificationCenter defaultCenter] postNotificationName:@"USB_DISCONNECTED" object:str];
        }
    });
}

2.类B 监听

//初始化
-(void)initNotifi
{
    [[MiUtil sharedInstance]register];
    
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(notificationHandler:) name:nil object:nil];
}
//销毁监听

-(void)destroyNotify{
    [[NSNotificationCenter defaultCenter] removeObserver:self name:@"USB_DISCONNECTED" object:nil];
}

//监听回调  [notification object] 是传的参数
-(void)notificationHandler:(NSNotification*)notification{
    if([notification.name compare:@"USB_CONNECTED"]==NSOrderedSame){
  
    }else if([notification.name compare:@"USB_DISCONNECTED"]==NSOrderedSame){
            NSLog(@"%@",[notification object]);
        
    }
}

name设置成nil是监听所有
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(notificationHandler:) name:@"USB_DISCONNECTED" object:nil];

[notification object]是参数

 

本文地址：https://blog.csdn.net/yonggandess/article/details/109612755