AVAudioSession.sharedInstance()导致其他App背景音乐被停止

参考文章：https://www.jianshu.com/p/3e0a399380df

在本App中AVAudioSession.sharedInstance()会使得其他App的背景音乐停止。应该本应用使用时候其他App背景音乐暂停，使用后恢复

1、可以在开启录音或播放时候

AVAudioSession.sharedInstance().setActive(true)

2、在录音完毕或播放完毕之后

AVAudioSession.sharedInstance().setActive(false, with: AVAudioSessionSetActiveOptions.notifyOthersOnDeactivation)

注意：如果使用AVCaptureSession的startRunning，使用完成后要主动调用stopRunning。不然setActive为false会报错：

[AVAudioSession setActive:withOptions:error:]: Deactivating an audio session that has running I/O. All I/O should be stopped or paused prior to deactivating the audio session.

代码举例：

        var isOtherAudioPlaying: Bool = false
        
        //播放代码
        do {
            let player =  try AVAudioPlayer.init(contentsOf: url)
            //            player.delegate = self
            player.prepareToPlay()
            isOtherAudioPlaying = AVAudioSession.sharedInstance().isOtherAudioPlaying
            try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
            try AVAudioSession.sharedInstance().setActive(true)
            player.play()
        } catch {
        }

        //录音代码
        do {
            let recorder = try AVAudioRecorder(url: url,
                                               settings: [AVFormatIDKey : NSNumber(value: kAudioFormatLinearPCM),
                                                          AVSampleRateKey : 8000.0 as NSNumber,
                                                          AVNumberOfChannelsKey : 1 as NSNumber,
                                                          AVEncoderBitDepthHintKey : 16 as NSNumber,
                                                          AVEncoderAudioQualityKey : AVAudioQuality.low.rawValue as NSNumber])
            
            recorder.delegate = self
            //            recorder.isMeteringEnabled = true
            if recorder.prepareToRecord() {
                isOtherAudioPlaying = AVAudioSession.sharedInstance().isOtherAudioPlaying
                try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayAndRecord)
                try AVAudioSession.sharedInstance().setActive(true)
                if recorder.record(forDuration:Double(60)) {
                } else {
                    print("Failed to record.")
                }
            } else {
                print("Failed to prepareToRecord.")
            }
        } catch {
        }

        //结束录音或播放之后

       guard isOtherAudioPlaying else {
return
        }
        do {
            try AVAudioSession.sharedInstance().setActive(false, with: AVAudioSessionSetActiveOptions.notifyOthersOnDeactivation)
        } catch {}