Android Studio Kotlin：Fragment录制音频存内部存储遇setAudioSource失败

使用Android Studio + Kotlin开发，尝试在Fragment页面录制音频并保存至内部存储时，持续出现setAudioSource failed异常，错误栈信息如下：

com.fypvpreventor.VpreventorFYP, PID: 23176
java.lang.RuntimeException: setAudioSource failed.
at android.media.MediaRecorder.native_setAudioSource(Native Method)
at android.media.MediaRecorder.setAudioSource(MediaRecorder.java:1923)
at com.fypvpreventor.VpreventorFYP.fragments.SensorFragment.onViewCreated(SensorFragment.kt:89)
at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:2987)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:546)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2189)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2106)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2002)
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:524)
at android.os.Handler.handleCallback(Handler.java:900)
at android.os.Handler.dispatchMessage(Handler.java:103)
at android.os.Looper.loop(Looper.java:219)
at android.app.ActivityThread.main(ActivityThread.java:8668)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1109)

解决步骤 #

• 检查并申请录音权限
  Android 6.0（API 23）及以上版本需动态申请RECORD_AUDIO权限，仅在Manifest声明无效。在Fragment中实现权限申请逻辑：

  private val RECORD_AUDIO_PERMISSION_REQUEST = 1001
  
  override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
      super.onViewCreated(view, savedInstanceState)
      if (ContextCompat.checkSelfPermission(requireContext(), Manifest.permission.RECORD_AUDIO)
          != PackageManager.PERMISSION_GRANTED
      ) {
          requestPermissions(arrayOf(Manifest.permission.RECORD_AUDIO), RECORD_AUDIO_PERMISSION_REQUEST)
      } else {
          initMediaRecorder()
      }
  }
  
  override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
      super.onRequestPermissionsResult(requestCode, permissions, grantResults)
      if (requestCode == RECORD_AUDIO_PERMISSION_REQUEST) {
          if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
              initMediaRecorder()
          } else {
              Toast.makeText(requireContext(), "需要录音权限才能录制音频", Toast.LENGTH_SHORT).show()
          }
      }
  }
  

  同时在AndroidManifest.xml中添加权限声明：

  <uses-permission android:name="android.permission.RECORD_AUDIO" />
  <uses-feature android:name="android.hardware.microphone" android:required="true" />
  

• 确认AudioSource参数合法性
  调用setAudioSource时必须使用有效常量，推荐使用MediaRecorder.AudioSource.MIC，避免使用已废弃或不存在的参数：

  mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC)
  

• 严格遵循MediaRecorder初始化顺序
  MediaRecorder的配置步骤必须按以下顺序执行，否则会触发异常：

  1. setAudioSource
  2. setOutputFormat
  3. setAudioEncoder
  4. setOutputFile
  5. prepare()

• 排查麦克风占用情况
  若设备上有其他应用（如通话、语音助手）正在使用麦克风，当前应用无法获取麦克风控制权，导致setAudioSource失败。提示用户关闭相关应用后重试。

• 确保内部存储路径正确
  保存音频到内部存储时，使用应用专属目录避免权限问题：

  val outputFile = File(requireContext().filesDir, "recording.mp3")
  mediaRecorder.setOutputFile(outputFile.absolutePath)
  

内容的提问来源于stack exchange，提问作者Destroyer King