iOS 可达性和应用挂起/恢复行为

Question

我正在使用 Apple 的 Reachability 示例代码来检测网络连接变化，并想知道一旦应用返回前台，如何获得准确的网络状态。

在我当前可见的 UIViewController 中，我正在注册为 kReachabilityChangedNotification 的观察者（与 Reachability 示例代码相同）并监听 UIApplicationWillEnterForegroundNotification 和 UIApplicationWillResignActiveNotification 事件。

在我当前可见的 UIViewController 中，就在应用挂起之前：

// While the app is in the foreground, I configure SCNetworkReachabilitySetCallback 
// At this point, I have lost connectivity.

[reachability startNotifier];

// this returns NotReachable, as expected
NetworkStatus status = [reachability currentReachabilityStatus];

现在暂停应用并更改 wifi 设置（更改网络设置以建立连接）

After app resume: (in the UIApplicationWillEnterForegroundNotification handler)
// this still returns NotReachable even though I now have connectivity.
NetworkStatus status = [reachability currentReachabilityStatus];

对我做的不正确有什么建议吗？

Answer 1

应用恢复后，试试这个：

//Reachability is the class from Apple's Reachability sample

Reachability *reachability = [Reachability reachabilityForLocalWiFi];

NetworkStatus netStatus = [reachability currentReachabilityStatus];

if (netStatus == NotReachable)
{
    NSLog(@"Not Reachable");
} else
{
    NSLog(@"Reachable");
}