iOS消息通知Notification的用法

1.发送消息

NSNotification *notification = [NSNotification notificationWithName:@"selectPosition" object:nil userInfo:@"codeABC" forKey:@"code"];
2 [[NSNotificationCenter defaultCenter]postNotification:notification];

2.接收消息

- (void)viewDidLoad {
    [super viewDidLoad];  
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(selectPosition:) name:@"selectPosition" object:nil];
}

- (void)selectPosition:(NSNotification *)notification
{
    NSString *code = [notification.userInfo objectForKey:@"code"];
}