Swift iOS - 当有 wifi 连接但没有互联网连接时该怎么办？

Question

我在我的 iOS 应用程序中使用 Alamofire。我在 viewWillAppear 和 AppDelegate 中使用 bool 值和 NSNotifications 来检查是否有互联网连接。如果没有 wifi 连接，则会出现一个弹出窗口以通知用户。如果有 wifi 连接，弹出窗口就会消失，一切正常。只要wifi显然无法正常工作，我就没有问题。

我正在参加一个聚会，有人向我解释说它的工作方式是它寻找 wifi 连接而不是互联网连接。例如。如果我有一个 wifi 路由器并且它已插入但路由器未连接到互联网 Alamofire 会将此视为成功连接，因为它实际上正在连接到 wifi 虽然它不知道 wifi 无法连接到互联网.

我只是在连接到开放网络的情况下，我的应用程序最初的响应好像我真的连接到了互联网（没有弹出窗口），但我无法连接到任何东西。wifi信号全开。在终端中，我运行了 ping，结果发现连接已死。我的应用程序无法区分。

在这样的情况下，如何让弹出窗口出现？

还有什么是 .case unknown ？

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!
    }()
}

应用委托：

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

        NetworkManager.sharedManager.startListening()

一些VC：

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

我遵循了AshleyMills Reachability文件（在下面添加），它用于google.com测试连接。

需要注意的是，我设置的方式是专门监视 viewWillAppear，并且在切换选项卡和推送/弹出/呈现视图控制器时效果最佳。在实际的 AshleyMills GitHub 存储库中，他使用 DispatchQueue.asyncAfter( .now() + 5) 计时器和其他代码来不断监视我的答案中未包含的内容。为了持续监控，您应该使用上面链接中的 ViewController 文件或我在该线程中的Firebase 答案

将其添加到viewWillAppear和viewWillDisappear：

var reachability: Reachability?
let reachabilityConnection = Reachability()!

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
        
    setupReachability("www.google.com") // inside China use www.alibaba.com
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    stopNotifier()
}

func setupReachability(_ hostName: String) {
    
    self.reachability = Reachability(hostname: hostName)
    
    startNotifier()
}

func startNotifier() {
    do {
        print("notifier started")

        try reachability?.startNotifier()

        monitorReachability()

    } catch {
        print("*****Could not start notifier*****")
    }
}

func monitorReachability() {
    
    reachability?.whenReachable = { [weak self] (_) in
        
        self?.reachabilityChanged()
    }
    reachability?.whenUnreachable = { [weak self] (_) in
        
        self?.reachabilityChanged()
    }
}

func reachabilityChanged() {
    let reachability = reachabilityConnection
    
    switch reachability.connection {
        
    case .wifi:
        print("----Reachable via WiFi")
    case .cellular:
        print("----Reachable via Cellular")
    case .none:
        print("----No Signal")
    }
}

func stopNotifier() {
    
    reachability?.stopNotifier()

    reachability = nil

    print("notifier stopped")
}

为 AshleyMills 文件创建一个文件并将其添加到其中。我将该文件命名为 Networkability：

import SystemConfiguration
import Foundation

public enum ReachabilityError: Error {
    case FailedToCreateWithAddress(sockaddr_in)
    case FailedToCreateWithHostname(String)
    case UnableToSetCallback
    case UnableToSetDispatchQueue
}

@available(*, unavailable, renamed: "Notification.Name.reachabilityChanged")
public let ReachabilityChangedNotification = NSNotification.Name("ReachabilityChangedNotification")

extension Notification.Name {
    public static let reachabilityChanged = Notification.Name("reachabilityChanged")
}

func callback(reachability: SCNetworkReachability, flags: SCNetworkReachabilityFlags, info: UnsafeMutableRawPointer?) {
    guard let info = info else { return }
    
    let reachability = Unmanaged<Reachability>.fromOpaque(info).takeUnretainedValue()
    reachability.reachabilityChanged()
}

public class Reachability {
    
    public typealias NetworkReachable = (Reachability) -> ()
    public typealias NetworkUnreachable = (Reachability) -> ()
    
    @available(*, unavailable, renamed: "Connection")
    public enum NetworkStatus: CustomStringConvertible {
        case notReachable, reachableViaWiFi, reachableViaWWAN
        public var description: String {
            switch self {
            case .reachableViaWWAN: return "Cellular"
            case .reachableViaWiFi: return "WiFi"
            case .notReachable: return "No Connection"
            }
        }
    }
    
    public enum Connection: CustomStringConvertible {
        case none, wifi, cellular
        public var description: String {
            switch self {
            case .cellular: return "Cellular"
            case .wifi: return "WiFi"
            case .none: return "No Connection"
            }
        }
    }
    
    public var whenReachable: NetworkReachable?
    public var whenUnreachable: NetworkUnreachable?
    
    @available(*, deprecated: 4.0, renamed: "allowsCellularConnection")
    public let reachableOnWWAN: Bool = true
    
    /// Set to `false` to force Reachability.connection to .none when on cellular connection (default value `true`)
    public var allowsCellularConnection: Bool
    
    // The notification center on which "reachability changed" events are being posted
    public var notificationCenter: NotificationCenter = NotificationCenter.default
    
    @available(*, deprecated: 4.0, renamed: "connection.description")
    public var currentReachabilityString: String {
        return "\(connection)"
    }
    
    @available(*, unavailable, renamed: "connection")
    public var currentReachabilityStatus: Connection {
        return connection
    }
    
    public var connection: Connection {
        guard isReachableFlagSet else { return .none }
        
        // If we're reachable, but not on an iOS device (i.e. simulator), we must be on WiFi
        guard isRunningOnDevice else { return .wifi }
        
        var connection = Connection.none
        
        if !isConnectionRequiredFlagSet {
            connection = .wifi
        }
        
        if isConnectionOnTrafficOrDemandFlagSet {
            if !isInterventionRequiredFlagSet {
                connection = .wifi
            }
        }
        
        if isOnWWANFlagSet {
            if !allowsCellularConnection {
                connection = .none
            } else {
                connection = .cellular
            }
        }
        
        return connection
    }
    
    fileprivate var previousFlags: SCNetworkReachabilityFlags?
    
    fileprivate var isRunningOnDevice: Bool = {
        #if targetEnvironment(simulator)
        return false
        #else
        return true
        #endif
    }()
    
    fileprivate var notifierRunning = false
    fileprivate let reachabilityRef: SCNetworkReachability
    
    fileprivate let reachabilitySerialQueue = DispatchQueue(label: "uk.co.ashleymills.reachability")
    
    fileprivate var usingHostname = false
    
    required public init(reachabilityRef: SCNetworkReachability, usingHostname: Bool = false) {
        allowsCellularConnection = true
        self.reachabilityRef = reachabilityRef
        self.usingHostname = usingHostname
    }
    
    public convenience init?(hostname: String) {
        guard let ref = SCNetworkReachabilityCreateWithName(nil, hostname) else { return nil }
        self.init(reachabilityRef: ref, usingHostname: true)
    }
    
    public convenience init?() {
        var zeroAddress = sockaddr()
        zeroAddress.sa_len = UInt8(MemoryLayout<sockaddr>.size)
        zeroAddress.sa_family = sa_family_t(AF_INET)
        
        guard let ref = SCNetworkReachabilityCreateWithAddress(nil, &zeroAddress) else { return nil }
        
        self.init(reachabilityRef: ref)
    }
    
    deinit {
        stopNotifier()
    }
}

public extension Reachability {
    
    // MARK: - *** Notifier methods ***
    func startNotifier() throws {
        guard !notifierRunning else { return }
        
        var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil)
        context.info = UnsafeMutableRawPointer(Unmanaged<Reachability>.passUnretained(self).toOpaque())
        if !SCNetworkReachabilitySetCallback(reachabilityRef, callback, &context) {
            stopNotifier()
            throw ReachabilityError.UnableToSetCallback
        }
        
        if !SCNetworkReachabilitySetDispatchQueue(reachabilityRef, reachabilitySerialQueue) {
            stopNotifier()
            throw ReachabilityError.UnableToSetDispatchQueue
        }
        
        // Perform an initial check
        reachabilitySerialQueue.async {
            self.reachabilityChanged()
        }
        
        notifierRunning = true
    }
    
    func stopNotifier() {
        defer { notifierRunning = false }
        
        SCNetworkReachabilitySetCallback(reachabilityRef, nil, nil)
        SCNetworkReachabilitySetDispatchQueue(reachabilityRef, nil)
    }
    
    // MARK: - *** Connection test methods ***
    @available(*, deprecated: 4.0, message: "Please use `connection != .none`")
    var isReachable: Bool {
        guard isReachableFlagSet else { return false }
        
        if isConnectionRequiredAndTransientFlagSet {
            return false
        }
        
        if isRunningOnDevice {
            if isOnWWANFlagSet && !reachableOnWWAN {
                // We don't want to connect when on cellular connection
                return false
            }
        }
        
        return true
    }
    
    @available(*, deprecated: 4.0, message: "Please use `connection == .cellular`")
    var isReachableViaWWAN: Bool {
        // Check we're not on the simulator, we're REACHABLE and check we're on WWAN
        return isRunningOnDevice && isReachableFlagSet && isOnWWANFlagSet
    }
    
    @available(*, deprecated: 4.0, message: "Please use `connection == .wifi`")
    var isReachableViaWiFi: Bool {
        // Check we're reachable
        guard isReachableFlagSet else { return false }
        
        // If reachable we're reachable, but not on an iOS device (i.e. simulator), we must be on WiFi
        guard isRunningOnDevice else { return true }
        
        // Check we're NOT on WWAN
        return !isOnWWANFlagSet
    }
    
    var description: String {
        let W = isRunningOnDevice ? (isOnWWANFlagSet ? "W" : "-") : "X"
        let R = isReachableFlagSet ? "R" : "-"
        let c = isConnectionRequiredFlagSet ? "c" : "-"
        let t = isTransientConnectionFlagSet ? "t" : "-"
        let i = isInterventionRequiredFlagSet ? "i" : "-"
        let C = isConnectionOnTrafficFlagSet ? "C" : "-"
        let D = isConnectionOnDemandFlagSet ? "D" : "-"
        let l = isLocalAddressFlagSet ? "l" : "-"
        let d = isDirectFlagSet ? "d" : "-"
        
        return "\(W)\(R) \(c)\(t)\(i)\(C)\(D)\(l)\(d)"
    }
}

fileprivate extension Reachability {
    func reachabilityChanged() {
        guard previousFlags != flags else { return }
        
        guard let reachable = whenReachable else { return }
        guard let unreachable = whenUnreachable else { return }
        print("?????>>>>>>\(reachable)")
        let block = connection != .none ? reachable : unreachable
        
        DispatchQueue.main.async {
            if self.usingHostname {
                print("USING HOSTNAME ABOUT TO CALL BLOCK")
            }
            block(self)
            self.notificationCenter.post(name: .reachabilityChanged, object:self)
        }
        
        previousFlags = flags
    }
    
    var isOnWWANFlagSet: Bool {
        #if os(iOS)
        return flags.contains(.isWWAN)
        #else
        return false
        #endif
    }
    var isReachableFlagSet: Bool {
        return flags.contains(.reachable)
    }
    var isConnectionRequiredFlagSet: Bool {
        return flags.contains(.connectionRequired)
    }
    var isInterventionRequiredFlagSet: Bool {
        return flags.contains(.interventionRequired)
    }
    var isConnectionOnTrafficFlagSet: Bool {
        return flags.contains(.connectionOnTraffic)
    }
    var isConnectionOnDemandFlagSet: Bool {
        return flags.contains(.connectionOnDemand)
    }
    var isConnectionOnTrafficOrDemandFlagSet: Bool {
        return !flags.intersection([.connectionOnTraffic, .connectionOnDemand]).isEmpty
    }
    var isTransientConnectionFlagSet: Bool {
        return flags.contains(.transientConnection)
    }
    var isLocalAddressFlagSet: Bool {
        return flags.contains(.isLocalAddress)
    }
    var isDirectFlagSet: Bool {
        return flags.contains(.isDirect)
    }
    var isConnectionRequiredAndTransientFlagSet: Bool {
        return flags.intersection([.connectionRequired, .transientConnection]) == [.connectionRequired, .transientConnection]
    }
    
    var flags: SCNetworkReachabilityFlags {
        var flags = SCNetworkReachabilityFlags()
        if SCNetworkReachabilityGetFlags(reachabilityRef, &flags) {
            print("Returning flags \(flags)")
            return flags
        } else {
            return SCNetworkReachabilityFlags()
        }
    }
}