当 wifi 重新打开时，Ashley Mills 可达性不发送通知？

Question

我有一个设置，使用 Ashley Mills Reachability，当应用程序的连接发生变化时，它应该使用 NotificationCenter 向应用程序发送通知。设置如下：

func reachabilityChanged(note: Notification) {

        let reachability = note.object as! Reachability

        switch reachability.connection {
        case .wifi:
            print("Reachable via WiFi")
        case .cellular:
            print("Reachable via Cellular")
        case .none:
            print("Network not reachable")
        }
    }

override func viewDidLoad() {
        super.viewDidLoad()


        NotificationCenter.default.addObserver(self, selector: #selector(self.reachabilityChanged), name: .reachabilityChanged, object: reachability)
        do{
            try reachability.startNotifier()
        }catch{
            print("could not start reachability notifier")
        }
    }

我的电脑（我正在运行打开模拟器）连接到 wifi，控制台准确地打印 "Reachable via Wifi"。关闭 wifi 会导致控制台再次准确打印 "Network not reachable"。但是，当我重新打开 wifi 时，我运行遇到了问题。 "Reachable via Wifi" 没有打印到日志中...事实上，没有任何内容打印到日志中。我不知道为什么会这样，也不知道如何解决。有人有什么想法吗？
这是可达性代码：

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: "Conection")
    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 (arch(i386) || arch(x86_64)) && os(iOS)
            return false
        #else
            return true
        #endif
    }()

    fileprivate var notifierRunning = false
    fileprivate let reachabilityRef: SCNetworkReachability

    fileprivate let reachabilitySerialQueue = DispatchQueue(label: "uk.co.ashleymills.reachability")

    required public init(reachabilityRef: SCNetworkReachability) {
        allowsCellularConnection = true
        self.reachabilityRef = reachabilityRef
    }

    public convenience init?(hostname: String) {

        guard let ref = SCNetworkReachabilityCreateWithName(nil, hostname) else { return nil }

        self.init(reachabilityRef: ref)
    }

    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 }

        let block = connection != .none ? whenReachable : whenUnreachable

        DispatchQueue.main.async {
            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) {
            return flags
        } else {
            return SCNetworkReachabilityFlags()
        }
    }
}

Answer 1

它在模拟器中每个运行只触发一次，但在真实的 iOS 设备上，它可以正常工作。

当 wifi 重新打开时，Ashley Mills 可达性不发送通知？

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