Swift -如何在循环时获取AVAudioPlayerNode的当前位置？

import AVFoundation

// 创建AVAudioEngine实例
let audioEngine = AVAudioEngine()

// 创建AVAudioPlayerNode实例
let audioPlayerNode = AVAudioPlayerNode()

// 将AVAudioPlayerNode添加到AVAudioEngine中
audioEngine.attach(audioPlayerNode)

// 加载音频文件
let audioFile = try AVAudioFile(forReading: audioURL)

// 连接音频文件到AVAudioPlayerNode
audioEngine.connect(audioPlayerNode, to: audioEngine.mainMixerNode, format: audioFile.processingFormat)

// 启动AVAudioEngine
try audioEngine.start()

// 获取当前位置的方法
func getCurrentPosition() -> AVAudioFramePosition? {
    guard let lastRenderTime = audioPlayerNode.lastRenderTime,
          let playerTime = audioPlayerNode.playerTime(forNodeTime: lastRenderTime) else {
        return nil
    }
    
    let sampleRate = audioFile.fileFormat.sampleRate
    let sampleTime = playerTime.sampleTime
    
    return AVAudioFramePosition(sampleTime * sampleRate)
}

// 在循环中获取当前位置
while true {
    if let currentPosition = getCurrentPosition() {
        print("当前位置：\(currentPosition)")
    }
}