如何在iOS中从MusicPlayer (用于Midi文件)中获取持续时间？

import AVFoundation

func getDurationFromMusicPlayer() -> TimeInterval? {
    guard let midiURL = Bundle.main.url(forResource: "example", withExtension: "mid") else {
        return nil
    }
    
    var musicSequence: MusicSequence?
    NewMusicSequence(&musicSequence)
    
    guard let sequence = musicSequence else {
        return nil
    }
    
    MusicSequenceFileLoad(sequence, midiURL as CFURL, .midiType, .smf_ChannelsToTracks)
    
    var musicPlayer: MusicPlayer?
    NewMusicPlayer(&musicPlayer)
    
    guard let player = musicPlayer else {
        return nil
    }
    
    MusicPlayerSetSequence(player, sequence)
    MusicPlayerPreroll(player)
    
    var beats: MusicTimeStamp = 0
    MusicSequenceGetBeatsForSeconds(sequence, Float64.greatestFiniteMagnitude, &beats)
    
    var seconds: Float64 = 0
    MusicSequenceGetSecondsForBeats(sequence, beats, &seconds)
    
    return TimeInterval(seconds)
}

// 调用函数来获取持续时间
if let duration = getDurationFromMusicPlayer() {
    print("Midi文件的持续时间为：\(duration)秒")
} else {
    print("无法获取Midi文件的持续时间")
}