kNetworkReachabilityChanged通知API的通知

Question

在我的项目中，我使用Reachability API。我遵循
Reachability API Documentation给出的代码示例。

在我的应用程序委托我已经实现的applicationDidFinishLaunching方法如下，

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 

    // Observe the kNetworkReachabilityChangedNotification. When that notification is posted, the 
    // method "reachabilityChanged" will be called. 
    [[NSNotificationCenter defaultCenter] addObserver: self selector: @selector(reachabilityChanged:) name: kReachabilityChangedNotification object: nil]; 

    hostReach = [[Reachability reachabilityWithHostName: NSLocalizedString(@"SERVICE_HOST_URL", nil)] retain]; 
    [hostReach startNotifier]; 
    [self updateReachabilityStatus:hostReach]; 

    self.rootViewController = [[SearchRootViewController alloc] initWithNibName:@"SearchRootView" bundle:nil]; 
    self.detailViewController = [[SearchDetailViewController alloc] initWithNibName:@"SearchView" bundle:nil]; 

    UINavigationController *rootViewNavigationController = [[UINavigationController alloc] initWithRootViewController:self.rootViewController]; 
    UINavigationController *detailViewnavigationController = [[UINavigationController alloc] initWithRootViewController:self.detailViewController]; 

    self.splitViewController = [[UISplitViewController alloc] init]; 
    self.splitViewController.viewControllers = [NSArray arrayWithObjects:rootViewNavigationController, detailViewnavigationController, nil]; 

    [rootViewNavigationController release]; 
    [detailViewnavigationController release]; 

    self.splitViewController.delegate = self.detailViewController; 

    [self.detailViewController setLeftViewController:self.rootViewController]; 

    [self.window addSubview:[self.splitViewController view]]; 
    [self.window makeKeyAndVisible]; 
    return YES; 
} 

当这个kNetworkReachabilityChangedNotification发布？我注意到它不会发布，直到我的detailViewController的视图出现。

但我想知道在视图出现之前的网络状态。所以，需要您的帮助来了解是否有可能？如果是的话，那么怎么样？

感谢名单

Answer 1

这可能需要一些时间来确定哪些网络连接可用：你问可达开始生成通知，但随后立即显示您的视图控制器......而你也只能在创建视图控制器后启动可达性通知，所以它是完全可能的发送通知之前您的视图控制器被实例化。

更好的方法是拥有一个可以在尝试建立网络状态时使用的持有视图。