从 AVAudioPlayer 设置 MPNowPlayingInfoCenter currentTime 和 songLength

Question

我在设置 MPNowPlayingInfoCenter 的 currentTime 和 songLength 时遇到问题。这是我的代码：

func updateNowPlayingCenter (title: String, artist: String, albumArt: AnyObject, currentTime: NSNumber, songLength: NSNumber, PlaybackRate: Double){

    var songInfo: Dictionary <NSObject, AnyObject> = [

        MPMediaItemPropertyTitle as NSObject: title as AnyObject,

        MPMediaItemPropertyArtist as NSObject: artist as AnyObject,

        MPMediaItemPropertyArtwork as NSObject: ???,

        MPNowPlayingInfoPropertyElapsedPlaybackTime as NSObject: currentTime,

        MPMediaItemPropertyPlaybackDuration as NSObject: songLength,

        MPNowPlayingInfoPropertyPlaybackRate as NSObject: PlaybackRate as AnyObject


    ]

    MPNowPlayingInfoCenter.default().nowPlayingInfo = songInfo as [NSObject : AnyObject] as! [String : Any]

}

这里是我在 viewWillAppear 中设置属性的地方：

updateNowPlayingCenter(title: titleText[thisSong], artist: authorText[thisSong], albumArt: ??? as AnyObject, currentTime: ???, songLength: ???, PlaybackRate: 1.0)

我尝试使用 audioPlayer.currentTime 和 audioPlayer.duration，但没有成功。我该怎么做呢？另外，我不知道如何设置 MPMediaItemPropertyArtwork 的图像。我的资产中有文件，图像名称等于 titleText[thisSong]。如果你也能帮助我，那就太棒了！谢谢！

Answer 1

Apple 的 Media Playback Programming Guide 提供了答案：

func setupNowPlaying() {
    // Define Now Playing Info
    var nowPlayingInfo = [String : Any]()
    nowPlayingInfo[MPMediaItemPropertyTitle] = "My Movie"
    if let image = UIImage(named: "lockscreen") {
        nowPlayingInfo[MPMediaItemPropertyArtwork] =
            MPMediaItemArtwork(boundsSize: image.size) { size in
                return image
        }
    }
    nowPlayingInfo[MPNowPlayingInfoPropertyElapsedPlaybackTime] = playerItem.currentTime().seconds
    nowPlayingInfo[MPMediaItemPropertyPlaybackDuration] = playerItem.asset.duration.seconds
    nowPlayingInfo[MPNowPlayingInfoPropertyPlaybackRate] = player.rate

    // Set the metadata
    MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo
}