加载选项卡后，请随时检查连接

Question

在我的项目中，我有在本网站上找到的代码，用于检查用户是否没有任何互联网（没有wifi或手机）。当没有连接的人打开选项卡时，代码工作，但是当他们首先打开选项卡然后失去连接时，它无法检测到。如何在加载选项卡后触发该功能并且之后失去连接？以下是代码：

import SystemConfiguration

func connectedToNetwork() -> Bool {

    var zeroAddress = sockaddr_in()
    zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
    zeroAddress.sin_family = sa_family_t(AF_INET)

    guard let defaultRouteReachability = withUnsafePointer(&zeroAddress, {
        SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0))
    }) else {
        return false
    }

    var flags : SCNetworkReachabilityFlags = []
    if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
        return false
    }

    let isReachable = flags.contains(.Reachable)
    let needsConnection = flags.contains(.ConnectionRequired)

    // For Swift 3, replace the last two lines by
    // let isReachable = flags.contains(.reachable)
    // let needsConnection = flags.contains(.connectionRequired)


    return (isReachable && !needsConnection)
}