相关疑难解决方法(0)

我有一门课，static var其中存储了当前的在线连接状态。我想ConnectionManager.online通过其他课程来观察价值。我想用KVO做到这一点，但是将static变量声明为dynamic会导致错误：

class ConnectionManager: NSObject {
    dynamic static var online = false
    // adding 'dynamic' declaration causes error:
    // "A declaration cannot be both 'final' and 'dynamic'
}

最优雅的方法是什么？

更新。这是我的KVO部分代码：

override func viewDidLoad() {
    super.viewDidLoad()

    ConnectionManager.addObserver(
        self,
        forKeyPath: "online",
        options: NSKeyValueObservingOptions(),
        context: nil
    )
}

override func observeValueForKeyPath(keyPath: String?, 
                                     ofObject object: AnyObject?, 
                                     change: [String : AnyObject]?, 
                                     context: UnsafeMutablePointer<Void>) {
    if keyPath == "online" {
        print("online status changed to: \(ConnectionManager.online)") …