创建 Reachability 侦听器
Apple 的 Reachability 类定期检查网络状态并提醒观察者更改。
Reachability *internetReachability = [Reachability reachabilityForInternetConnection];
[internetReachability startNotifier];
Apple 的 Reachability 类定期检查网络状态并提醒观察者更改。
Reachability *internetReachability = [Reachability reachabilityForInternetConnection];
[internetReachability startNotifier];