ios - 如何在 Swift 中将 IsConnected bool 返回到函数外部

Question

我想将 var isConnected 返回到函数外部，以便在按钮中调用它(无论其是否正确)。

func checkReachability(isConnected: @escaping (Bool)->()) -> Bool {

    var wifiMessage = ""
    var isConnected = false

    if currentReachabilityStatus == .reachableViaWiFi {
        print("User is connected to the internet via wifi.")
        let interface = CNCopySupportedInterfaces()
        for i in 0..<CFArrayGetCount(interface) {
            let interfaceName: UnsafeRawPointer = CFArrayGetValueAtIndex(interface, i)
            let rec = unsafeBitCast(interfaceName, to: AnyObject.self)

            if let unsafeInterfaceData = CNCopyCurrentNetworkInfo("\(rec)" as CFString), let interfaceData = unsafeInterfaceData as? [String : AnyObject] {
                // connected wifi
                wifiMessage = (String(describing: interfaceData["SSID"]))

                SSIDAtual.text = "Conexão Atual:"+wifiMessage

                StatusCon.text = "Status da Conexão: Conectado."

                print(wifiMessage as Any)

                isConnected = true
            }

        }

    } else {
        SSIDAtual.text = "Conexão Atual: Nenhuma Conexão."
        StatusCon.text = "Status da Conexão: Desconectado."
        print("There is no internet connection")

        isConnected = false

    }
    print(isConnected)
    return isConnected
}

我想在按钮操作中调用 while 内的 boolean 值:

@IBAction func LoginWEP(_ sender: Any) {
    let SSID = SSIDText.text
    let Pass = PassText.text
    var cont:Int
cont = 0
let contf:Int
contf = 10

let wifiConfig = NEHotspotConfiguration(ssid: SSID!, passphrase: Pass!, isWEP: true)

wifiConfig.joinOnce = false

NEHotspotConfigurationManager.shared.apply(wifiConfig) { error in

    if let error = error{
        print("Error: " + (error.localizedDescription))

    }else {
        while cont < contf{
            sleep(1)
            cont += 1




        }
        print("Connected.")

    }
}
    self.view.endEditing(true)
}

Answer 1

根据任务的不同，您可以采取多种方式:

1)使用全局变量

var isConnected: Bool?

func checkReachability() {

    var wifiMessage = ""

    if currentReachabilityStatus == .reachableViaWiFi {

        ...

                self.isConnected = true

        }

    } else {
        ...

        self.isConnected = false

    }

    print(isConnected)
    return isConnected
} 

用法:

 NEHotspotConfigurationManager.shared.apply(wifiConfig) { error in

     ...

         isConnected(self.isConnected)

     }
}

2)闭包中的返回值

你的功能:

func checkReachability(completion: @escaping (_ isConnected: Bool) -> Void) {

    var wifiMessage = ""

    if currentReachabilityStatus == .reachableViaWiFi {
        print("User is connected to the internet via wifi.")
        let interface = CNCopySupportedInterfaces()
        for i in 0..<CFArrayGetCount(interface) {
            let interfaceName: UnsafeRawPointer = CFArrayGetValueAtIndex(interface, i)
            let rec = unsafeBitCast(interfaceName, to: AnyObject.self)

            if let unsafeInterfaceData = CNCopyCurrentNetworkInfo("\(rec)" as CFString), let interfaceData = unsafeInterfaceData as? [String : AnyObject] {
                // connected wifi
                wifiMessage = (String(describing: interfaceData["SSID"]))

                SSIDAtual.text = "Conexão Atual:"+wifiMessage

                StatusCon.text = "Status da Conexão: Conectado."

                print(wifiMessage as Any)


                completion(true)


            }

        }


    } else {
        SSIDAtual.text = "Conexão Atual: Nenhuma Conexão."
        StatusCon.text = "Status da Conexão: Desconectado."
        print("There is no internet connection")

        completion(false)

    }
}

用法:

checkReachability { (isConnected) in
     //Your code
}