使用AVAudioPlayer播放多个音频文件

我在主StoryBoard上创建了3个UIButton。

当我按下“ Button1”或“ Button2”时，每个播放音频文件（“播放器1”，“播放器2”。），并且在播放音频时，UIButton设置为selected。

我希望“ Button3”连续实现多个功能。这意味着当我按下“按钮3”时，应首先播放“玩家3”，然后播放该“玩家1”，再播放该“玩家2”。

但是，当我按“ Button3”时，“播放器1”和“播放器2”同时播放，因为前一个播放没有延迟。

我发现设置AVAudioPlayer的委托或使用AVQueuePlayer可以解决问题，但是我发现很难进行更改。

    fileprivate var player1:AVAudioPlayer?
    fileprivate var player2:AVAudioPlayer?
    fileprivate var player3:AVAudioPlayer?


    @IBAction func pushButton1(sender: UIButton) {
        audioPlayer1(url: url1)
    }

    @IBAction func pushButton2(sender: UIButton) {
        audioPlayer2(url: url2)
    }

    @IBAction func pushButton3(_ sender: UIButton) {
        audioPlayer3(url: url1, url2: url2, url3: url3)
    }


    func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {
        if (player === player1) {
            yourButton1.isSelected = false
        } else if (player === player2) {
            yourButton2.isSelected = false
        } else if (player === player3) {

            //"player 1" and "player 2" are played at same time

            yourButton3.isSelected = false
            player1!.play()
            yourButton1.isSelected = true
            player2!.play()
            yourButton2.isSelected = false
        }
    }


    func audioPlayer1(url: URL) {
        do {
            try player1 = AVAudioPlayer(contentsOf:url)
            player1!.play()
            yourButton1.isSelected = true
            player1!.delegate = self
        } catch {
            print(error)
        }
    }

    func audioPlayer2(url: URL) {
        do {
            try player2 = AVAudioPlayer(contentsOf:url)
            player2!.play()
            yourButton2.isSelected = true
            player2!.delegate = self

        } catch {
            print(error)
        }
    }

    func audioPlayer3(url: URL, url2: URL, url3: URL) {
        do {
            try player3 = AVAudioPlayer(contentsOf:url3)
            try player1 = AVAudioPlayer(contentsOf: url1)
            try player2 = AVAudioPlayer(contentsOf: url2)
            player3!.play()
            yourButton3.isSelected = true
            player3!.delegate = self
            player1!.delegate = self
        } catch {
            print(error)
        }
    }
}

更改代码

    var queue = AVQueuePlayer()
    var items = [AVPlayerItem]()


    override func viewDidLoad() {
        super.viewDidLoad()
        player1?.delegate = self
        player2?.delegate = self
        player3?.delegate = self

        let asset1 = AVPlayerItem(url: url1)
        let asset2 = AVPlayerItem(url: url2)
        let asset3 = AVPlayerItem(url: url3)
        let asset4 = AVPlayerItem(url: url4)

        items = [asset1, asset2, asset3, asset4]

        queue = AVQueuePlayer(items: items)
        for item in queue.items() {
            NotificationCenter.default.addObserver(self, selector: #selector(playerItemDidReachEnd(notification:)), name: .AVPlayerItemDidPlayToEndTime, object: item)
        }

    }
 @IBAction func pushButton3(_ sender: UIButton) {
        //audioPlayer3(url: url1, url2: url2)
        sender.isSelected = true
        queue.play()
    }
 func playerItemDidReachEnd(notification: NSNotification) {

        if notification.object as? AVPlayerItem == items[0] {
            yourButton3.isSelected = false
            yourButton1.isSelected = true
        }

        if notification.object as? AVPlayerItem == items[1] {
            yourButton1.isSelected = false
            yourButton2.isSelected = true
        }

        if notification.object as? AVPlayerItem == items[2] {
            yourButton2.isSelected = false
            yourButton4.isSelected = true
            //yourButton1.isSelected = true
        }

        if notification.object as? AVPlayerItem == items[3] {
            yourButton4.isSelected = false
            print("item 3")
        }