TL;DR

Github上的例子：https://github.com/JakubMazur/SO52243428
您不应该将nil分配给此nowPlayingInfo。
要实现这一点，您应该做的是：
1.停止播放（不需要，但清理你创建的内容很好）
1.将会话设置为非活动状态
1.清除nowPlayingInfo
因此，代码看起来像：

self.player?.stop() // Where self.player is AVAudioPlayer
try? self.session?.setActive(false, with: .notifyOthersOnDeactivation) // Where self.session is AVAudioSession. You should do it with do-catch to good error catching.
MPNowPlayingInfoCenter.default().nowPlayingInfo = [:]

它的行为是这样的：

编辑：

我写了尽可能简单的例子来尝试它。在Github https://github.com/JakubMazur/SO52243428上可以找到。如果符合你的情况，请随意检查。

对我来说是工作。

func setupNowPlaying() {
    var nowPlayingInfo = [String : Any]()
    nowPlayingInfo[MPMediaItemPropertyTitle] = "my video"
    if let image = UIImage(named: "video image") {
        nowPlayingInfo[MPMediaItemPropertyArtwork] =
            MPMediaItemArtwork(boundsSize: image.size) { size in
                return image
        }
    }
    let playerItem = self.player?.currentItem
    
    nowPlayingInfo[MPNowPlayingInfoPropertyElapsedPlaybackTime] = playerItem?.currentTime().seconds
    nowPlayingInfo[MPMediaItemPropertyPlaybackDuration] = playerItem?.asset.duration.seconds
    nowPlayingInfo[MPNowPlayingInfoPropertyPlaybackRate] = self.player?.rate
 
    
    MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo
    
    UIApplication.shared.beginReceivingRemoteControlEvents()
    
}

func closeVideo() {
    self.player?.pause()
    
    let sessionAV = AVAudioSession.sharedInstance()
    try? sessionAV.setActive(false, options: AVAudioSession.SetActiveOptions.notifyOthersOnDeactivation)
    
    
    MPNowPlayingInfoCenter.default().nowPlayingInfo = [:]
    
    UIApplication.shared.endReceivingRemoteControlEvents()
}