ios - 有没有办法在音频 B 也开始播放后修复音频 A 的播放？

Question

我正在构建一个应用程序，用户可以在其中选择要播放的音频文件。这通常有效，即使在屏幕锁定时也能播放。问题在于，在用户更改音频文件后，第一个音频文件仍在后台播放，并与用户想要收听的文件重叠。

let player: AVPlayer = {
        let avPlay = AVPlayer()
        avPlay.allowsExternalPlayback = false
        avPlay.automaticallyWaitsToMinimizeStalling = false
        return avPlay
    }()

fileprivate func setupLockScreenCurrentTime(){
        var nowPlayingInfo = MPNowPlayingInfoCenter.default().nowPlayingInfo
//      nowPlayingInfo = nil

        guard let currentItem = player.currentItem else{return}
        let durationInSecs = CMTimeGetSeconds(currentItem.duration)
//      let elapsed = CMTimeGetSeconds(player.currentTime())
        nowPlayingInfo?[MPMediaItemPropertyPlaybackDuration] = durationInSecs

        MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo
    }
fileprivate func playSermon(){
        let credential = URLCredential(user: "1234user" , password: "password", persistence: .forSession)
        let protectionSpace = URLProtectionSpace(host: "example.com", port: 443, protocol: "https", realm: "Restricted", authenticationMethod: NSURLAuthenticationMethodHTTPBasic)
        URLCredentialStorage.shared.setDefaultCredential(credential, for: protectionSpace)
        let ssurl = SermonHelper.sharedInstance.url
        let urlNew:String = ssurl.replacingOccurrences(of: " ", with: "%20")
        guard let url = URL(string: urlNew) else {return}
        let playerItem = AVPlayerItem(url: url)
        player.replaceCurrentItem(with: playerItem)
        player.isMuted = false
        player.play()
        observePlayerCurrentTime()

    }

fileprivate func setupRemoteControl(){
        UIApplication.shared.beginReceivingRemoteControlEvents()

        let commandCenter = MPRemoteCommandCenter.shared()
        commandCenter.playCommand.isEnabled = true
        commandCenter.playCommand.addTarget { (_) -> MPRemoteCommandHandlerStatus in
            self.player.play()
            self.enlargeEpisodeImageView()
            self.playPauseButton.setImage(UIImage(named: "my_pause2"), for: .normal)
            self.setupElapsedTime(rate: 1)
            return .success
        }

        commandCenter.pauseCommand.isEnabled = true
        commandCenter.pauseCommand.addTarget { (_) -> MPRemoteCommandHandlerStatus in
            self.player.pause()
            self.shrinkEpisodeImageView()
            self.playPauseButton.setImage(UIImage(named: "my_play2"), for: .normal)
            self.setupElapsedTime(rate: 0)
            return .success
        }

        commandCenter.togglePlayPauseCommand.isEnabled = true
        commandCenter.togglePlayPauseCommand.addTarget { (_) -> MPRemoteCommandHandlerStatus in
            if self.player.timeControlStatus == .playing {
                self.player.pause()
                self.shrinkEpisodeImageView()
                self.playPauseButton.setImage(UIImage(named: "my_play2"), for: .normal)
            }
            else {
                self.player.play()
                self.enlargeEpisodeImageView()
                self.playPauseButton.setImage(UIImage(named: "my_pause2"), for: .normal)
            }
            return .success
        }
        commandCenter.skipForwardCommand.isEnabled = true
        commandCenter.skipForwardCommand.addTarget { (_) -> MPRemoteCommandHandlerStatus in
            self.seekToCurrentTime(delta: 15)
            let t = CMTimeAdd(self.player.currentTime(), CMTimeMake(15, 1))
            MPNowPlayingInfoCenter.default().nowPlayingInfo?[MPNowPlayingInfoPropertyElapsedPlaybackTime] = CMTimeGetSeconds(t)
            return .success
        }

        commandCenter.skipBackwardCommand.isEnabled = true
        commandCenter.skipBackwardCommand.addTarget { (_) -> MPRemoteCommandHandlerStatus in
            self.seekToCurrentTime(delta: -15)
            let n = CMTimeAdd(self.player.currentTime(), CMTimeMake(-15, 1))
            MPNowPlayingInfoCenter.default().nowPlayingInfo?[MPNowPlayingInfoPropertyElapsedPlaybackTime] = CMTimeGetSeconds(n)
            return .success
        }
    }

我希望正在播放的音频被用户选择的新音频文件替换，但我从同时播放的两个文件中获取了音频。

Answer 1

当您在 playSermon() 中用新声音替换当前声音之前停止播放当前声音时，代码中的任何地方都不会指示。尝试这样做。这很可能会解决您的问题。