斯威夫特：我怎样才能让一个监听器报告连接何时丢失以及何时恢复？

Posted 2023-03-10

【中文标题】斯威夫特：我怎样才能让一个监听器报告连接何时丢失以及何时恢复？

【英文标题】：Swift: How can I have a listener that reports when connection is lost and when it comes back?

【发布时间】：2015-11-23 19:17:53

【问题描述】：

我想在我的 ios 应用程序启动时调用一个方法，但我只想在有连接时调用这个方法。我发现在Objective-C中你可以使用Reachable，但事实证明这个方法不是Swift的一部分。

我找到了一个名为 Reachability.swift 的 pod，我正在使用提供的示例：

override func viewWillAppear(animated: Bool) 
    let reachability: Reachability
    do 
        reachability = try Reachability.reachabilityForInternetConnection()
     catch 
        print("Unable to create Reachability")
        return
    
    NSNotificationCenter.defaultCenter().addObserver(self,
        selector: "reachabilityChanged:",
        name: ReachabilityChangedNotification,
        object: reachability)

    do 
        try reachability.startNotifier()
     catch 
        print("This is not working.")
            return
    


func reachabilityChanged(note: NSNotification) 

    let reachability = note.object as! Reachability

    if reachability.isReachable() 
        if reachability.isReachableViaWiFi() 
            print("Reachable via WiFi")
         else 
            print("Reachable via Cellular")
        
     else 
        print("Not reachable")
    

但是，这不能正常工作。我只在进入那个 ViewController 时工作，而不是在我打开和关闭 WiFi 时工作。

【参考方案1】：

我已经通过将reachability 声明为 ViewController 的实例变量来解决这个问题：

var reachability: Reachability!

所以这个变量应该从方法viewWillAppear中删除。

斯威夫特 2

override func viewWillAppear(animated: Bool) 
    do 
        reachability = try Reachability.reachabilityForInternetConnection()
     catch 
        print("Unable to create Reachability")
        return
    

    NSNotificationCenter.defaultCenter().addObserver(self,
        selector: "reachabilityChanged:",
        name: ReachabilityChangedNotification,
        object: reachability)

    do 
        try reachability.startNotifier()
     catch 
        print("This is not working.")
        return
    



func reachabilityChanged(note: NSNotification) 

    let reachability = note.object as! Reachability

    if reachability.isReachable() 
        if reachability.isReachableViaWiFi() 
            print("Reachable via WiFi")
         else 
            print("Reachable via Cellular")
        
     else 
        print("Not reachable")
    

Swift 3（由Burning提供）

var reachability: Reachability!
override func viewWillAppear(_ animated: Bool) 
    super.viewWillAppear(animated)
    reachability = Reachability()
    NotificationCenter.default.addObserver(self, selector: #selector(self.reachabilityChanged(_:)), name: Notification.Name.reachabilityChanged, object: reachability)

    do 
        try reachability?.startNotifier()
     catch 
        print("This is not working.")
        return
    



func reachabilityChanged(_ note: NSNotification) 

    let reachability = note.object as! Reachability

    if reachability.connection != .none 
        if reachability.connection == .wifi 
            print("Reachable via WiFi")
         else 
            print("Reachable via Cellular")
        
     else 
        print("Not reachable")
    

这工作正常:)。

【讨论】：

嘿，我尝试将其用于我的项目，但似乎在 swift 3 .reachabilityForInternetConnection() 中无法识别：您能帮我解决一下吗？