Ios 显示可达性状态警报

我正在使用ashleymills的可达性：

在Xcode 7中，我编写了一个函数来显示可达性状态的警报

然而，警报从未出现

这是我的密码：

let reachability = Reachability.reachabilityForInternetConnection()
reachability!.whenReachable = { reachability in
    if reachability.isReachableViaWiFi() {
        let alertController = UIAlertController(title: "Alert", message: "Reachable via WiFi", preferredStyle: .Alert)
        let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

        alertController.addAction(defaultAction)

        self.presentViewController(alertController, animated: true, completion: nil)
    }
    else {
        let alertController = UIAlertController(title: "Alert", message: "Reachable via Cellular", preferredStyle: .Alert)
        let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

        alertController.addAction(defaultAction)

        self.presentViewController(alertController, animated: true, completion: nil)
    }
}

reachability!.whenUnreachable = { reachability in
    let alertController = UIAlertController(title: "Alert", message: "Please connect to internet", preferredStyle: .Alert)
    let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

    alertController.addAction(defaultAction)

    self.presentViewController(alertController, animated: true, completion: nil)
}

reachability!.startNotifier()

---

请用这个替换你的代码，它应该可以工作，在swift 1.2之后，

Reachability

中可能有一个bug，所以这里我只是检查它是否可以访问，我认为这已经足够了

在我看来，您不必检查是wifi还是手机，警报背后的原因没有显示，因为它没有进入块来显示警报：

let useClosures = false

class ViewController: UIViewController {

    let reachability = Reachability.reachabilityForInternetConnection()

    override func viewDidLoad() {
        super.viewDidLoad()

        if (useClosures) {
            reachability?.whenReachable = { reachability in
                print("Reachable")
            }
            reachability?.whenUnreachable = { reachability in
                print("Unreachable")
            }
        } else {
            NSNotificationCenter.defaultCenter().addObserver(self, selector: "reachabilityChanged:", name: ReachabilityChangedNotification, object: reachability)
        }

        reachability?.startNotifier()

        // Initial reachability check when the app starts
        if let reachability = reachability {
              dispatch_async(dispatch_get_main_queue()) {
            if reachability.isReachable() {
                let alertController = UIAlertController(title: "Alert", message: "Reachable", preferredStyle: .Alert)
                let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

                alertController.addAction(defaultAction)

                self.presentViewController(alertController, animated: true, completion: nil)
            } else {
                let alertController = UIAlertController(title: "Alert", message: "Please connect to internet", preferredStyle: .Alert)
                let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

                alertController.addAction(defaultAction)

                self.presentViewController(alertController, animated: true, completion: nil)
            }
            }
        }
    }

    deinit {

        reachability?.stopNotifier()

        if (!useClosures) {
            NSNotificationCenter.defaultCenter().removeObserver(self, name: ReachabilityChangedNotification, object: nil)
        }
    }


    func reachabilityChanged(note: NSNotification) {
        let reachability = note.object as! Reachability
        // Initial reachability check while surfing in the app
        if reachability.isReachable() {
            let alertController = UIAlertController(title: "Alert", message: "Reachable", preferredStyle: .Alert)
            let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

            alertController.addAction(defaultAction)

            self.presentViewController(alertController, animated: true, completion: nil)

        } else {
            let alertController = UIAlertController(title: "Alert", message: "Please connect to internet", preferredStyle: .Alert)
            let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

            alertController.addAction(defaultAction)

            self.presentViewController(alertController, animated: true, completion: nil)
        }
    }
}

---

注意：你说你的应用程序中有webView，请记住，当它可以访问时，你必须刷新或更新它。

请用这个替换你的代码，它应该可以工作，在swift 1.2之后，

可访问性中可能有一个bug，所以我在这里只是检查它是否可以访问，我认为这就足够了

在我看来，您不必检查是wifi还是手机，警报背后的原因没有显示，因为它没有进入块来显示警报：

let useClosures = false

class ViewController: UIViewController {

    let reachability = Reachability.reachabilityForInternetConnection()

    override func viewDidLoad() {
        super.viewDidLoad()

        if (useClosures) {
            reachability?.whenReachable = { reachability in
                print("Reachable")
            }
            reachability?.whenUnreachable = { reachability in
                print("Unreachable")
            }
        } else {
            NSNotificationCenter.defaultCenter().addObserver(self, selector: "reachabilityChanged:", name: ReachabilityChangedNotification, object: reachability)
        }

        reachability?.startNotifier()

        // Initial reachability check when the app starts
        if let reachability = reachability {
              dispatch_async(dispatch_get_main_queue()) {
            if reachability.isReachable() {
                let alertController = UIAlertController(title: "Alert", message: "Reachable", preferredStyle: .Alert)
                let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

                alertController.addAction(defaultAction)

                self.presentViewController(alertController, animated: true, completion: nil)
            } else {
                let alertController = UIAlertController(title: "Alert", message: "Please connect to internet", preferredStyle: .Alert)
                let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

                alertController.addAction(defaultAction)

                self.presentViewController(alertController, animated: true, completion: nil)
            }
            }
        }
    }

    deinit {

        reachability?.stopNotifier()

        if (!useClosures) {
            NSNotificationCenter.defaultCenter().removeObserver(self, name: ReachabilityChangedNotification, object: nil)
        }
    }


    func reachabilityChanged(note: NSNotification) {
        let reachability = note.object as! Reachability
        // Initial reachability check while surfing in the app
        if reachability.isReachable() {
            let alertController = UIAlertController(title: "Alert", message: "Reachable", preferredStyle: .Alert)
            let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

            alertController.addAction(defaultAction)

            self.presentViewController(alertController, animated: true, completion: nil)

        } else {
            let alertController = UIAlertController(title: "Alert", message: "Please connect to internet", preferredStyle: .Alert)
            let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)

            alertController.addAction(defaultAction)

            self.presentViewController(alertController, animated: true, completion: nil)
        }
    }
}

注意：您说过您的应用程序中有webView，请记住，您必须在其可访问时进行刷新或更新。
谢谢！只需测试您的代码，但警报永远不会出现。@GPH，您将此代码放在哪里？在
视图中加载
？顺便说一句，在我的情况下，它显示！是的，在ViewController.swifit的viewDidLoad功能中，它仅在启动应用程序时显示，如果启动应用程序后互联网连接发生变化，则不会显示警报。顺便说一句，添加代码后，webview无法显示任何内容。我修复了一些问题，并添加了您的代码。它显示错误如下谢谢！只需测试您的代码，但警报永远不会出现。@GPH，您将此代码放在哪里？在
视图中加载
？顺便说一句，在我的情况下，它显示！是的，在ViewController.swifit的viewDidLoad功能中，它仅在启动应用程序时显示，如果启动应用程序后互联网连接发生变化，则不会显示警报。顺便说一句，添加代码后，webview无法显示任何内容。我修复了一些问题，并添加了您的代码。它显示错误如下：我认为问题可能是没有在主线程上调用闭包，因此将
UIAlertController
代码包装在
dispatch\u async（dispatch\u get\u main\u queue（））{…}
中应该可以解决问题，我认为问题可能是没有在主线程上调用闭包，因此，将
UIAlertController
代码包装在
dispatch\u async（dispatch\u get\u main\u queue（））{…}
中应该可以解决这个问题