ios - 尝试使用 Alamofire 检查 iOS 设备上的互联网连接

Question

我使用以下代码检查互联网连接:

class Reachability {

    let networkReachabilityManager = Alamofire.NetworkReachabilityManager(host: "www.google.com")

    func checkForReachability() {
        self.networkReachabilityManager?.listener = { status in
            print("Network Status: \(status)")
            switch status {
            case .notReachable:
                print("no internet connection detected")
            //Show error here (no internet connection)
            case .reachable(_), .unknown:
                print("internet connection availible")
            }
        }
        self.networkReachabilityManager?.startListening()
    }
}

当连接存在时，成功调用.reachable中的block。但是在连接缺失的情况下没有任何调用，为什么？

我这样调用它(保持对类的引用，所以它没有被释放)

class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    let reachabilityManager = Reachability()

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        window = UIWindow(frame: UIScreen.main.bounds)
        reachabilityManager.checkForReachability()
        return true
    }

Answer 1

创建检查连通性的通用类

import Foundation
import Alamofire

class Connectivity {
    class func isConnectedToInternet() -> Bool {
        return NetworkReachabilityManager()!.isReachable
    }
}

然后在需要的地方调用函数

if !Connectivity.isConnectedToInternet() {
    // show Alert
    return
}