ios - 如何在 if 语句中检查 NSNotification

Question

我正在尝试运行以下代码，除非发送了 NSNotification。我不知道如何将 NSNotification 放在 if 语句中:

if (!self.subViewControllerProv) {
    self.subViewControllerProv = [[ProvViewController alloc] init];
}


[[NSNotificationCenter defaultCenter] addObserver:self
    selector:@selector(handleNotification:) name:@"SomeNotification" object:nil];

回顾一下:如果观察到 NSNotification 消息，则 alloc 和 init ProvViewController 如果没有，则不要't.

Answer 1

那么做这样的事情怎么样:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleNotification) name:@"SomeNotification" object:nil];

然后

-(void) handleNotification {
    //BOOL _hasBeenSent in your interface
    _hasBeenSent = YES;
}

然后在你的代码中

if(_hasBeenSent) {
    NSLog(@"The notification has been sent!");
}