在 Swift 應用程序中斷開音頻設備時如何停止音頻播放？

Question

我正在編寫一個 Swift 應用程序，它從 Web Radio URL 流式傳輸音頻，但我無法使其在音頻路由更改時正常運行，尤其是在斷開音頻設備連接時。

我參考了 Apple 文檔的這一頁，但是我對示例中如何使用headphonesConnected變量以及如何不僅涵蓋耳機，還涵蓋其他設備（如藍牙耳機、CarPlay 設備等）感到困惑。

基本上我需要我的應用程序通過在外部音頻設備（耳機、BT 耳機、CarPlay 設備）斷開連接時停止播放來遵循 iOS 指南。

Answer 1

先做一個觀察者：

NotificationCenter.default.addObserver(self, selector: #selector(handleRouteChange(_:)), name: AVAudioSession.routeChangeNotification, object: nil)

並實施 handleRouteChange：

 @objc func handleRouteChange(_ notification: Notification) {
          
         //bron: https://developer.apple.com/library/archive/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/HandlingAudioHardwareRouteChanges/HandlingAudioHardwareRouteChanges.html#//apple_ref/doc/uid/TP40007875-CH5-SW3
        
          guard let userInfo = notification.userInfo,
          let reasonValue = userInfo[AVAudioSessionRouteChangeReasonKey] as? UInt,
          let reason = AVAudioSession.RouteChangeReason(rawValue:reasonValue) else {return}
        
          switch reason {
            
          case .routeConfigurationChange:
          
               let session = AVAudioSession.sharedInstance()
          
               for output in session.currentRoute.outputs where output.portType == AVAudioSession.Port.headphones {
            
                    play()
            
                    break
               
               }
            
               for output in session.currentRoute.outputs where output.portType == AVAudioSession.Port.airPlay {

                    play()

                    break

               }

               for output in session.currentRoute.outputs where output.portType == AVAudioSession.Port.carAudio {

                    if isPlaying && autoplayCaraudio {
                         
                         play()

                    }

                    break

               }

          case .oldDeviceUnavailable:
            
               if let previousRoute = userInfo[AVAudioSessionRouteChangePreviousRouteKey] as? AVAudioSessionRouteDescription {

                    for output in previousRoute.outputs where output.portType == AVAudioSession.Port.headphones {

                         pause()

                         break

                    }

                    for output in previousRoute.outputs where output.portType == AVAudioSession.Port.airPlay {

                         pause()

                         break

                    }

                    for output in previousRoute.outputs where output.portType == AVAudioSession.Port.carAudio {

                         pause()

                         break

                    }

               }
            
          default: ()
            
        }
        
    }