ios - 使用remoteControlReceived控制音乐时遇到问题

Question

我有 MusicPlayer View Controller ，您可以播放一些本地 mp3 文件。我需要为我的应用程序启用 remoteControlReceived 才能在应用程序外部更改音乐(播放/暂停、下一首)。我的问题是切换按钮仅在应用程序位于 MusicPlayerViewController 中时才起作用。例如，如果此 vc 关闭或转到后台，这些操作将不再起作用! 。首先，我在 MusicPlayerViewController 中设置这些通知:

  override func viewDidLoad() {
        super.viewDidLoad()

        //Control Music

        NotificationCenter.default.addObserver(self, selector: #selector(playSong), name: NSNotification.Name("playSong"), object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(nextSong), name: NSNotification.Name("nextSong"), object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(previousSong), name: NSNotification.Name("previousSong"), object: nil)

}

然后在AppDelegate中:

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {


  //Play music when it's on BG
        do {
            try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
            print("AVAudioSession Category Playback OK")
            do {
                try AVAudioSession.sharedInstance().setActive(true)
                print("AVAudioSession is Active")
            } catch let error as NSError {
                print(error.localizedDescription)
            }
        } catch let error as NSError {
            print(error.localizedDescription)
        }

        UIApplication.shared.beginReceivingRemoteControlEvents()

}



 override func remoteControlReceived(with event: UIEvent?) {
        if event!.type == UIEventType.remoteControl{
            switch event!.subtype{
            case UIEventSubtype.remoteControlPlay:
                NotificationCenter.default.post(name: NSNotification.Name("playSong"), object: nil)

            case UIEventSubtype.remoteControlPause:
                NotificationCenter.default.post(name: NSNotification.Name("playSong"), object: nil)

            case UIEventSubtype.remoteControlNextTrack:
                NotificationCenter.default.post(name: NSNotification.Name("nextSong"), object: nil)

            case UIEventSubtype.remoteControlPreviousTrack:
                NotificationCenter.default.post(name: NSNotification.Name("previousSong"), object: nil)

            default:
                print("There is an issue with the control")
            }
        }
    }

我无法从任何地方控制 AVPlayer 是什么问题!

PS: I also setup playing music in AppDelegate

Answer 1

您需要在AVAudioPlayer上应用类别。因此，您需要在分配 AVAudioPlayer 之后编写以下代码。

//分配你的音频播放器然后

do {
    try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
    print("AVAudioSession Category Playback OK")
    do {
        try AVAudioSession.sharedInstance().setActive(true)
        print("AVAudioSession is Active")
    } catch let error as NSError {
        print(error.localizedDescription)
    }
} catch let error as NSError {
    print(error.localizedDescription)
}

UIApplication.shared.beginReceivingRemoteControlEvents()

希望这对您有帮助。