如何在AVAudioPlayer开始播放音频时准确地获得通知？

Question

注意：在将标题标记为重复之前，请仔细阅读标题（和问题）。问题是关于AVAudioPlayer而不是AVPlayer。

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所以根据AVAudioPlayer的文档

open func play() -> Bool /* sound is played asynchronously. */

我需要在音频开始时准确地向用户显示一个弹出窗口。当我们调用play()时不是这样。

[如果有玩家停止播放但没有开始播放，则有一个委托呼叫：（。

我找不到有关如何确切知道音频何时开始的任何方法。有什么办法可以检查吗？

Answer 1

我也面临同样的问题，只是决定基于AVPlayer创建一个新类：

import AVFoundation
import UIKit

 class AudioManager {

    private init() {}

    public static let shared = AudioManager()

    var player: AVPlayer?
    var item: AVPlayerItem?
    var layer: AVPlayerLayer?
    var currentUrl: URL?

    var pauseTime: CMTime?
    var endOfTrackObserver: Any?

    func startPlayContentOf(url: URL?) {

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(self.playerItemDidReachEnd(notification:)),
                                               name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
                                               object: self.player?.currentItem)

        guard let newAudioUrl = url else { return }
        let newAudioItem = AVPlayerItem(url: newAudioUrl)


        if let currentUrl = self.currentUrl, currentUrl == newAudioUrl {
            //same track
            if let playing = self.player?.isPlaying, playing == true  {
                self.pauseTime = self.player?.currentTime()
                self.pause()
            } else {
                self.player = AVPlayer(playerItem: newAudioItem)
                self.player?.volume = 3
                self.player?.seek(to: self.pauseTime ?? CMTime.zero)
                self.layer = AVPlayerLayer(player: self.player)
                self.layer?.frame = CGRect(x: 0, y: 0, width: 10, height: 10)
                self.layer?.backgroundColor = UIColor.clear.cgColor
                guard let layer = self.layer else { return }
                UIApplication.shared.keyWindow?.rootViewController?.view.layer.insertSublayer(layer, at: 0)
                self.play()
            }
        } else {
            //new track
            self.pauseTime = nil
            self.pause()
            self.player = AVPlayer(playerItem: newAudioItem)
            self.player?.volume = 3
            self.layer = AVPlayerLayer(player: self.player)
            self.layer?.frame = CGRect(x: 0, y: 0, width: 10, height: 10)
            self.layer?.backgroundColor = UIColor.clear.cgColor
            guard let layer = self.layer else { return }
            UIApplication.shared.keyWindow?.rootViewController?.view.layer.insertSublayer(layer, at: 0)
            self.play()
        }

        self.currentUrl = newAudioUrl
    }

    func playOrPause() {
        guard self.player != nil else { return }
        if self.player!.isPlaying {
            self.player!.pause()
        } else {
            self.player?.replaceCurrentItem(with: self.item)
            self.player!.play()
        }
    }

    func pause() {
        guard self.player != nil else { return }
        self.player!.pause()
    }

    func play() {
        guard self.player != nil else { return }
        self.player!.play()
    }

    @objc func playerItemDidReachEnd(notification: Notification) {
        self.pauseTime = nil
    }

}