AVAudioSession从未停止过

Question

我正在尝试将我的AVAudioSession设置为非活动状态以恢复到正常状态。

我的话语函数：

class SSpeech : NSObject, AVSpeechSynthesizerDelegate {

    var group = DispatchGroup();
    var queue = DispatchQueue(label: "co.xxxx.speech", attributes: [])

    class var sharedInstance: SSpeech {
        struct Static {
            static var instance: SSpeech?
        }
        if !(Static.instance != nil) {
            Static.instance = SSpeech()
        }
       return Static.instance!
    }

   required override init() {
       super.init();
       self.speechsynt.delegate = self;
   }

   deinit {
      print("deinit SSpeech")
   }

   let audioSession = AVAudioSession.sharedInstance();
   var speechsynt: AVSpeechSynthesizer = AVSpeechSynthesizer()
   var queueTalks = SQueue<String>();

   func pause() {
        speechsynt.pauseSpeaking(at: .word)
   }

   func talk(_ sentence: String, languageCode code:String = SUtils.selectedLanguage.code, withEndPausing: Bool = false) {
       if SUser.sharedInstance.currentUser.value!.speechOn != 1 {
           return
        }

        queue.async{            
            self.queueTalks.enQueue(sentence)
            do {
                let category = AVAudioSessionCategoryPlayback;
                var categoryOptions = AVAudioSessionCategoryOptions.duckOthers
                if #available(iOS 9.0, *) {
                    categoryOptions.formUnion(AVAudioSessionCategoryOptions.interruptSpokenAudioAndMixWithOthers)
                 }
                try self.audioSession.setCategory(category, with: categoryOptions)
                try self.audioSession.setActive(true);
            } catch _ {
                return;
            }

            self.utteranceTalk(sentence, initSentence: false, speechsynt: self.speechsynt, languageCode:code, withEndPausing: withEndPausing)

            do {
                try self.audioSession.setCategory(AVAudioSessionCategoryPlayback, with: AVAudioSessionCategoryOptions.mixWithOthers)
            } catch _ {
                return;
            }
        }
    }

    func utteranceTalk(_ sentence: String, initSentence: Bool, speechsynt: AVSpeechSynthesizer, languageCode:String = "en-US", withEndPausing: Bool = false){
        if SUser.sharedInstance.currentUser.value!.speechOn != 1 {
            return
        }

        let nextSpeech:AVSpeechUtterance = AVSpeechUtterance(string: sentence)
        nextSpeech.voice = AVSpeechSynthesisVoice(language: languageCode)
        if !initSentence {
            nextSpeech.rate = 0.4;
        }

        if(withEndPausing){
            nextSpeech.postUtteranceDelay = 0.2;
        }
        speechsynt.speak(nextSpeech)
    }


    func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance:AVSpeechUtterance) {
        print("Speaker has finished to talk")

        queue.async {
               do {
                   try self.audioSession.setActive(false, with: AVAudioSessionSetActiveOptions.notifyOthersOnDeactivation)
               }
               catch {}
           }
       }
    }
}

我的方法被正确调用，但是当utterance完成时，我的audioSession仍然是活动的。我试过很多方法，但都不管用。

Answer 1

您不能停止或停用AudioSession，您的应用程序会在启动时获取它。Documentation

音频会话是应用程序和iOS之间的中介，用于配置应用程序的音频行为。在启动时，您的应用程序会自动为提供一个单独的音频会话。

因此，方法-setActive:不会使您的AudioSession“活动”，它只是将其类别和模式配置付诸实施。为了回到“正常状态”，你可以设置default settings或者直接调用setActive(false, with:.notifyOthersOnDeactivation)，这就足够了。

Answer 2

来自documentation of AVAudioSession的一部分

讨论

如果另一个活动音频会话的优先级高于您的音频会话(例如，电话呼叫)，并且两个音频会话都不允许混合，则激活音频会话的尝试将失败。如果任何关联的音频对象(如队列、转换器、播放器或录音机)当前正在运行，则停用您的会话将失败。

我的猜测是，未能停用会话是因为您的queue正在运行的进程，正如我在文档引用中突出显示的那样。

也许您应该使停用过程同步而不是异步，或者确保您的queue下所有正在运行的操作都已被处理。

试一试：

func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance:AVSpeechUtterance) {
        print("Speaker has finished to talk")

        queue.sync { // <---- `async` changed to `sync`
               do {
                   try self.audioSession.setActive(false, with: AVAudioSessionSetActiveOptions.notifyOthersOnDeactivation)
               }
               catch {}
           }
       }
    }

Answer 3

我建议使用AvAudioPlayer。它们有非常简单的启动和停止命令。

首先将音频播放器声明为变量

var SoundEffect: AVAudioPlayer!

然后选择您需要的文件

    let path = Bundle.main.path(forResource: "Untitled2.wav", ofType:nil)!
                    let url = URL(fileURLWithPath: path)
    let sound = try AVAudioPlayer(contentsOf: url)
                        SoundEffect = sound
                        sound.numberOfLoops = -1
                        sound.play()

并停止音频播放器

if SoundEffect != nil {
            SoundEffect.stop()
            SoundEffect = nil
        }