这应该可以解决问题。
class ViewController: UIViewController { // MARK: Properties let notificationCenter = NSNotificationCenter.defaultCenter() // MARK: Lifecycle override func viewDidAppear(animated: Bool) { super.viewDidAppear(animated) notificationCenter.addObserver(self, selector: #selector(systemVolumeDidChange), name: "AVSystemController_SystemVolumeDidChangeNotification", object: nil ) } override func viewDidDisappear(animated: Bool) { super.viewDidDisappear(animated) notificationCenter.removeObserver(self) } // MARK: AVSystemPlayer - Notifications func systemVolumeDidChange(notification: NSNotification) { print(notification.userInfo?["AVSystemController_AudioVolumeNotificationParameter"] as? Float) }}
