ios - Swift SimplePing 不起作用

Question

我正在使用 SimplePing 来获取我的 swift 应用程序中的延迟，但我没有得到任何结果。

这是从 SO 中的示例中提取的代码:

import Foundation

public typealias SimplePingClientCallback = (String?)->()

public class SimplePingClient: NSObject {
    static let singletonPC = SimplePingClient()

    private var resultCallback: SimplePingClientCallback?
    private var pingClinet: SimplePing?
    private var dateReference: NSDate?

    public static func pingHostname(hostname: String, andResultCallback callback: SimplePingClientCallback?) {
        singletonPC.pingHostname(hostname, andResultCallback: callback)
    }

    public func pingHostname(hostname: String, andResultCallback callback: SimplePingClientCallback?) {
        resultCallback = callback
        pingClinet = SimplePing(hostName: hostname)
        pingClinet?.delegate = self
        pingClinet?.start()
    }
}

extension SimplePingClient: SimplePingDelegate {
    public func simplePing(pinger: SimplePing, didStartWithAddress address: NSData) {
        pinger.sendPingWithData(nil)
    }

    public func simplePing(pinger: SimplePing, didFailWithError error: NSError) {
        resultCallback?(nil)
    }

    public func simplePing(pinger: SimplePing!, didSendPacket packet: NSData!) {
        dateReference = NSDate()
    }

    public func simplePing(pinger: SimplePing!, didFailToSendPacket packet: NSData!, error: NSError!) {
        pinger.stop()
        resultCallback?(nil)
    }

    public func simplePing(pinger: SimplePing, didReceiveUnexpectedPacket packet: NSData) {
        pinger.stop()
        resultCallback?(nil)
    }

    public func simplePing(pinger: SimplePing!, didReceivePingResponsePacket packet: NSData!) {
        pinger.stop()

        guard let dateReference = dateReference else { return }

        //timeIntervalSinceDate returns seconds, so we convert to milis
        let latency = NSDate().timeIntervalSinceDate(dateReference) * 1000

        resultCallback?(String(format: "%.f", latency))
    }
}

为了在我的 viewController 中调用 SimplePing，我这样做了:

let simplePingClient = SimplePingClient()
        simplePingClient.pingHostname("www.apple.com") { latency in
        print("Your latency is \(latency ?? "unknown")")
        self.labelTempsReponse?.text = latency
        }

当我在这一行放置断点时:

simplePingClient.pingHostname("www.apple.com") { latency in

所有结果均为零(resultCallBack、pingClient 和 dateReference)。我做了一个研究来解决这个问题，我发现了一个 question与我的相似，但在 objective-c 中。

谁能帮帮我？

Answer 1

SimplePingClient 中的签名与它尝试实现的 SimplePingDelegate 协议(protocol)不匹配。也许这些曾经在一些早期版本中匹配过，但从 Swift 5/XCode 12.2 开始并使用 Apple's SimplePing code最后更新于 2016 年，他们没有。有些数据类型错误，有些参数标签不匹配，有些参数丢失。这意味着 SimplePingClient 永远不会得到它的回调，因为 SimplePing 在委托(delegate)对象中寻找匹配的签名，但没有找到，并跳过回调。

此外，因为 SimplePing.h 将这些委托(delegate)方法声明为可选，所以不会出现编译器错误。

要查看错误并让 XCode 为您编写协议(protocol) stub ，注释掉 SimplePing.h 中 SimplePingDelegate 定义中的@optional(行142).

为了让 SimplePingClient 正常工作，我需要对 SimplePingClient 类扩展进行更改:

extension SimplePingClient: SimplePingDelegate {
    
    public func simplePing(_ pinger: SimplePing, didStartWithAddress address: Data) {
        pinger.send(with: nil)
    }

    public func simplePing(_ pinger: SimplePing, didFailWithError error: Error) {
        resultCallback?(nil)
    }

    public func simplePing(_ pinger: SimplePing, didSendPacket packet: Data, sequenceNumber:UInt16) {
        dateReference = Date()
    }

    public func simplePing(_ pinger: SimplePing, didFailToSendPacket packet: Data, sequenceNumber: UInt16, error: Error) {
        pinger.stop()
        resultCallback?(nil)
    }

    public func simplePing(_ pinger: SimplePing, didReceiveUnexpectedPacket packet: Data) {
        pinger.stop()
        resultCallback?(nil)
    }

    public func simplePing(_ pinger: SimplePing, didReceivePingResponsePacket packet: Data, sequenceNumber:UInt16) {
        pinger.stop()

        guard let dateReference = dateReference else { return }

        //timeIntervalSinceDate returns seconds, so we convert to milis
        let latency = Date().timeIntervalSince(dateReference ) * 1000

        resultCallback?(String(format: "%.f", latency))
    }
}