注意不要忘了import AFNetworking

let manager = AFNetworkReachabilityManager.shared()
manager.setReachabilityStatusChange { (status) in
    manager.stopMonitoring()
    switch (status) {
    case .notReachable:
        break

    case .unknown:
        break

    case.reachableViaWiFi:
        break

    case .reachableViaWWAN:
        break
    }
}
manager.startMonitoring()