MPNowPlayingInfoCenter 不显示详细信息答案

【问题标题】：MPNowPlayingInfoCenter not showing detailsMPNowPlayingInfoCenter 不显示详细信息
【发布时间】：2021-09-26 08:45:22
【问题描述】：

今天我花了几个小时试图弄清楚为什么MPNowPlayingInfoCenter 不起作用，但没有成功。我希望它在控制中心和锁屏中显示信息，媒体是视频。

问题来了：

我有一个名为 GlobalAVPlayer 的单例类，它包含一个 AVPlayerViewController。它是一个单例，因为必须只有一个，而且我需要全局访问它。

class GlobalAVPlayer: NSObject {
static let sharedInstance = GlobalAVPlayer()

private var _currentVideo: Video?

var playerViewController = AVPlayerViewController()

var isPlaying: Bool = false
var almostPlaying: Bool = false
var hasItemToPlay: Bool = false

var currentVideo: Video?
{
    set {
        _currentVideo = newValue
        notify_VideoChanged()
    }
    get {
        return _currentVideo
    }
}

private var player: AVPlayer!

override init()
{
    super.init()
    player = AVPlayer()
    playerViewController.player = player
    
    player.addObserver(self, forKeyPath: "rate", options: NSKeyValueObservingOptions.New, context: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(didPlayToEnd), name: "AVPlayerItemDidPlayToEndTimeNotification", object: nil)
    
}

func itemToPlay(item: AVPlayerItem)
{
    if let player = player {
        almostPlaying = true
        hasItemToPlay = true
        player.replaceCurrentItemWithPlayerItem(item)
    }
}

func didPlayToEnd()
{
    print("[GlobalAVPlayer] End video notification")
    let time = CMTimeMakeWithSeconds(0, 1)
    player.seekToTime(time)
}
func play()
{
    if player.rate == 0
    {
        player.play()
        if player.rate != 0 && player.error == nil
        {
            isPlaying = true
            print("[GlobalAVPlayer] Playing video without errors")
        }
    }
}

func pause()
{
    if player.rate == 1
    {
        player.pause()
        if player.rate == 0 && player.error == nil
        {
            isPlaying = false
            print("[GlobalAVPlayer] Pausing video without errors")
        }
    }
}

func notify_PlaybackChanged()
{
    NSNotificationCenter.defaultCenter().postNotificationName("globalAVPlayerPlaybackChanged", object: self)
}

func notify_VideoChanged()
{
    NSNotificationCenter.defaultCenter().postNotificationName("globalAVPlayerVideoChanged", object: self)
}

override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) {
    if keyPath == "rate" {
        let newRate = change!["new"] as! Int
        //rate = 0 (il player è fermo)      rate = 1 (il player sta andando)
        self.isPlaying = newRate == 1 ? true : false
        notify_PlaybackChanged()
    }
}

deinit
{
    player.removeObserver(self, forKeyPath: "rate", context: nil)
}
}

应用程序启动时调用一次init，之后我使用“itemToPlay”方法更改视频。我也正确（我认为）在 AppDelegate 中配置了音频会话：

do
    {
        let session = AVAudioSession.sharedInstance()
        try session.setCategory(AVAudioSessionCategoryPlayback)
        try session.setActive(true)
    }
    catch
    {
        print("[AppDelegate] Something went wrong")
    }

我尝试将MPNowPlayingInfoCenter.defaultCenter().nowPlayingInfo = something 放在任何地方，但是当我将其放入play() 方法时，我最多可以在控制中心看到视频标题1 秒钟。之后它消失了，播放控件变灰了。信息已正确存储，因为当我将nowPlayingInfo 内容打印到控制台时，一切都按预期进行。我尝试在不同的地方使用becomeFirstResponder 和UIApplication.beginReceivingRemoteControlEvents，但没有成功。

谢谢

【问题讨论】：

标签： ios swift

【解决方案1】：

从 iOS 10 开始，AVPlayerViewController 中有一个名为 updatesNowPlayingInfoCenter 的 BOOL 属性，其默认值为：YES。改成NO：

//playerController is an instance of AVPlayerViewController
if ([self.playerController respondsToSelector:@selector(setUpdatesNowPlayingInfoCenter:)])
{
    self.playerController.updatesNowPlayingInfoCenter = NO;
}

【讨论】：