Alamofire - 當有wifi連接但沒有互聯網連接時該怎麼辦？

Question

我在我的iOS應用程序中使用Alamofire。我在viewWillAppear和AppDelegate中使用NSNotifications中的bool值來檢查是否有互聯網連接。如果沒有WiFi連接，彈出窗口會通知用戶。如果有wifi連接，彈出消失，一切正常。只要WiFi顯然不工作，我沒有問題。

我在聚會上，有人向我解釋，它的工作方式是它尋找無線連接而不是互聯網連接。例如，如果我有一個無線路由器，它已插入，但路由器沒有連接到互聯網阿拉莫菲爾將這視爲一個成功的連接，因爲它實際上連接到WiFi，雖然它不知道無線連接不能連接到互聯網。

我只是在我連接到一個開放網絡的情況下，我的應用程序最初回應，就好像我實際上連接到互聯網（沒有彈出），但我無法連接到任何東西。無線信號已滿。在終端，我跑了一個ping，結果證明連接已經死亡。我的應用程序無法區分差異。

如何使彈出出現在這樣的sitaution？

什麼是.case未知？

Alamofire.Swift：

import Foundation 
import Alamofire 

open class NetworkManager { 

    open static var sharedManager: NetworkReachabilityManager = { 

     let reachabilityManager = NetworkReachabilityManager() 

     reachabilityManager?.listener = { (status) in 

      switch status { 

      case .notReachable: 
       print("The network is not reachable") 
       NotificationCenter.default.post(name: NSNotification.Name(rawValue: "unsuccessful"), object: nil) 

      case .unknown : //??????? 
       print("It is unknown wether the network is reachable") 
       //I'm not sure whether to put a Notification for successful or unsuccessful??? 

      case .reachable(.ethernetOrWiFi): 
       print("The network is reachable over the WiFi connection") 
       NotificationCenter.default.post(name: NSNotification.Name(rawValue: "successful"), object: nil) 

      case .reachable(.wwan): 
       print("The network is reachable over the WWAN connection") 
       NotificationCenter.default.post(name: NSNotification.Name(rawValue: "successful"), object: nil) 
      } 
     } 

     reachabilityManager?.startListening() 
     return reachabilityManager! 
    }() 
} 

的AppDelegate：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool { 

     NetworkManager.sharedManager.startListening() 

SomeVC：

override func viewWillAppear() { 
     super.viewWillAppear() 

     NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(successful), name: "successful", object: nil) 

     NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(unsuccessful), name: "unsuccessful", object: nil) 

     if NetworkManager.sharedManager.isReachable == true{ 
      self.successful() 
     }else{ 
      self.unsuccessful() 
     } 

     if NetworkManager.sharedManager.isReachableOnWWAN == true{ 
      self.successful() 
     }else{ 
      self.unsuccessful() 
     } 

     if NetworkManager.sharedManager.isReachableOnEthernetOrWiFi == true{ 
      self.successful() 
     }else{ 
      self.unsuccessful() 
     } 
} 

func successful(){ 
    //dismiss pop up 
} 

func unsuccessful(){ 
    //show pop up 
} 

deinit{ 
    NSNotificationCenter.defaultCenter().removeObserver(self, name: "successful", object: nil) 
    NSNotificationCenter.defaultCenter().removeObserver(self, name: "unsuccessful", object: nil) 
} 
} 

Answer 1

可以初始化NetworkReachabilityManager與主機，例如，谷歌的主機，因爲默認情況下是0.0.0.0

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

當您開始監聽可達性管理器執行ping主機。如果網絡可用，您可以緩存SSID並在SSID更改時再次ping。

對於case .unknown更好地通知不成功。

例得到SSID（它不會在模擬器工作）：

func fetchSSIDInfo() -> String? { 
     if let interfaces = CNCopySupportedInterfaces() { 
      for i in 0..<CFArrayGetCount(interfaces){ 
       let interfaceName: UnsafeRawPointer = CFArrayGetValueAtIndex(interfaces, i) 
       let rec = unsafeBitCast(interfaceName, to: AnyObject.self) 
       let unsafeInterfaceData = CNCopyCurrentNetworkInfo("\(rec)" as CFString) 

       if let unsafeInterfaceData = unsafeInterfaceData as? Dictionary<AnyHashable, Any> { 
        return unsafeInterfaceData["SSID"] as? String 
       } 
      } 
     } 
     return nil 
    } 

Answer 2

對於那些誰是有問題的可達性和這個答案並不能幫助遵循此YouTube VID：

https://youtu.be/wDZmz9IsB-8

他使用Ashly Mills。他解釋得很好，而且很有效。

Answer 3

下面是這兩個解決方案組成的答案：Pavle Mijatovic和Yasin Ugurlu

創建一個新的類，並將其命名連接和複製和粘貼下面的代碼在它的內部：

import Foundation 
import SystemConfiguration 

class Connection { 

    class func isConnectedToNetwork() -> Bool { 

     var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0)) 
     zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress)) 
     zeroAddress.sin_family = sa_family_t(AF_INET) 

     guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, { 
      $0.withMemoryRebound(to: sockaddr.self, capacity: 1) { 
       SCNetworkReachabilityCreateWithAddress(nil, $0) 
      } 
     }) else { 
      return false 
     } 

     var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0) 
     if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == false { 
      return false 
     } 

     let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0 
     let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0 

     return isReachable && !needsConnection 

    } 

    class func isInternetAvailable(webSiteToPing: String?, completionHandler: @escaping (Bool) -> Void) { 

     // 1. Check the WiFi Connection 
     guard isConnectedToNetwork() else { 
      completionHandler(false) 
      return 
     } 

     // 2. Check the Internet Connection but possibly use www.apple.com or www.alibaba.com instead of google.com because it's not available in China 
     var webAddress = "https://www.google.com" // Default Web Site 
     if let _ = webSiteToPing { 
      webAddress = webSiteToPing! 
     } 

     guard let url = URL(string: webAddress) else { 
      completionHandler(false) 
      print("could not create url from: \(webAddress)") 
      return 
     } 

     let urlRequest = URLRequest(url: url) 
     let session = URLSession.shared 
     let task = session.dataTask(with: urlRequest, completionHandler: { (data, response, error) in 
      if error != nil || response == nil { 
       completionHandler(false) 
      } else { 
       completionHandler(true) 
      } 
     }) 
     task.resume() 
    } 
} 

在任何視圖控制器你用它在裏面viewDidLoad這樣稱呼它：

override func viewDidLoad() { 
     super.viewDidLoad() 

     // if in china usewww.apple.com or www.alibaba.com instead 
     Connection.isInternetAvailable(webSiteToPing: "https://www.google.com", completionHandler: { 
      (bool) in 

      if bool{ 
       print("Internet connection is good") 
      }else{ 
       print("No internet connection can be found") 
      } 
     }) 
} 

我發現了一些事情是隻看到毫秒工作一次，因爲如果連接可用"Internet connection is good"打印但如果我去飛行模式"No internet connection can be found"不打印。這不是積極傾聽，這讓我覺得我必須連接到通知？另一件事是，如果你在中國，那麼這是行不通的，因爲谷歌在中國不可用。也許一個更好的網站將檢查www.apple.com或www.alibaba.com，因爲它似乎無處不在。

Connection.isInternetAvailable(webSiteToPing: "https://www.apple.com"... 

或

Connection.isInternetAvailable(webSiteToPing: "https://www.alibaba.com"...