如何在Swift 4中通过发送方检索userData？

let userData = ["key": "value"]
NotificationCenter.default.post(name: NSNotification.Name("NotificationName"), object: nil, userInfo: userData)

NotificationCenter.default.addObserver(self, selector: #selector(handleNotification(_:)), name: NSNotification.Name("NotificationName"), object: nil)

@objc func handleNotification(_ notification: Notification) {
    if let userData = notification.userInfo as? [String: Any] {
        // 在这里使用userData进行操作
        let value = userData["key"]
        // ...
    }
}