迅捷的背景音乐延迟

Question

我尝试使背景音乐无缝循环，同时有一个不循环的部分，但切换AVAudioPlayers时会有延迟。当songA停止并且songB开始时发生延迟。 这是代码。

lazy var songA: AVAudioPlayer? = {
    guard let url = Bundle.main.url(forResource: "A", withExtension: "wav") else {
        return nil
    }
    do {
        let player = try AVAudioPlayer(contentsOf: url)
        let x = player
        x.delegate=self
        player.numberOfLoops = 0
        player.prepareToPlay()
        return player
    } catch {
        return nil
    }
}()
lazy var songB: AVAudioPlayer? = {
    guard let url = Bundle.main.url(forResource: "B", withExtension: "wav") else {
        return nil
    }
    do {
        let player = try AVAudioPlayer(contentsOf: url)
        player.numberOfLoops = -1
        player.prepareToPlay()
        return player
    } catch {
        return nil
    }
}()
func multiTrack(songA: AVAudioPlayer, songB: AVAudioPlayer) {
    masterStop()
    songA.play()
    while songA.isPlaying==true {
        if songA.isPlaying==false{
            songB.play()
            songA.stop()
            songA.prepareToPlay()
        }
    }
    songB.play()
    songA.stop()
    songA.prepareToPlay()
    songA.currentTime=0
}