Expo Audio iPhone后台录音停止问题求助

针对你用Expo Audio开发的录音应用在iPhone后台停止的问题，以下是几个关键修复点：

1. 修正音频模式配置 #

你当前的setAudioModeAsync配置缺少后台保持活跃的核心参数，需要补充以下内容：

await Audio.setAudioModeAsync({
  allowsRecordingIOS: true,
  playsInSilentModeIOS: true,
  stayActiveInBackgroundIOS: true, // 关键：允许应用后台保持音频活跃状态
  interruptionModeIOS: Audio.INTERRUPTION_MODE_IOS_DO_NOT_MIX, // 避免被其他音频打断录音
  shouldDuckAndroid: false,
  interruptionModeAndroid: Audio.INTERRUPTION_MODE_ANDROID_DO_NOT_MIX,
});

2. 自定义录音配置，强制开启后台录音 #

不要直接使用默认的RecordingOptionsPresets.HIGH_QUALITY，手动配置iOS专属的enableBackgroundRecording参数——这是后台录音必须开启的开关：

const recordingOptions = {
  android: {
    audioEncoding: Audio.RECORDING_OPTION_ANDROID_AUDIO_ENCODING_AAC,
    sampleRate: 44100,
    numberOfChannels: 2,
    bitRate: 128000,
  },
  ios: {
    audioQuality: Audio.RECORDING_OPTION_IOS_AUDIO_QUALITY_HIGH,
    sampleRate: 44100,
    numberOfChannels: 2,
    bitRate: 128000,
    format: Audio.RECORDING_OPTION_IOS_FORMAT_M4A,
    enableBackgroundRecording: true, // 必须开启此参数才能后台录音
  },
};

const { recording } = await Audio.Recording.createAsync(recordingOptions);

3. 确保app.json配置生效 #

你的app.json配置本身没问题，但注意修改后必须重新构建iOS应用（不能用Expo Go预览，需要通过eas build或expo build:ios生成安装包部署到真机），Expo Go无法完整测试后台权限功能。

4. 清理无关代码 #

你代码里定义的LOCATION_TASK_NAME属于位置任务配置，和音频后台功能无关，直接移除即可，避免造成混淆。

5. 真机测试注意事项 #

• 必须用物理iPhone测试，模拟器的后台行为和真机不一致，无法准确验证后台录音功能；
• 测试时关闭手机的低电量模式，该模式会限制应用后台活动。

修改后的完整startRecording函数：

async function startRecording() {
  try {
    console.log('Requesting permissions..');
    const permissionResponse = await Audio.requestPermissionsAsync();
    if (!permissionResponse.granted) {
      setMessage('需要录音权限才能继续');
      return;
    }

    await Audio.setAudioModeAsync({
      allowsRecordingIOS: true,
      playsInSilentModeIOS: true,
      stayActiveInBackgroundIOS: true,
      interruptionModeIOS: Audio.INTERRUPTION_MODE_IOS_DO_NOT_MIX,
      shouldDuckAndroid: false,
      interruptionModeAndroid: Audio.INTERRUPTION_MODE_ANDROID_DO_NOT_MIX,
    });

    console.log('Starting recording..');
    const recordingOptions = {
      android: {
        audioEncoding: Audio.RECORDING_OPTION_ANDROID_AUDIO_ENCODING_AAC,
        sampleRate: 44100,
        numberOfChannels: 2,
        bitRate: 128000,
      },
      ios: {
        audioQuality: Audio.RECORDING_OPTION_IOS_AUDIO_QUALITY_HIGH,
        sampleRate: 44100,
        numberOfChannels: 2,
        bitRate: 128000,
        format: Audio.RECORDING_OPTION_IOS_FORMAT_M4A,
        enableBackgroundRecording: true,
      },
    };
    const { recording } = await Audio.Recording.createAsync(recordingOptions);
    setRecording(recording);
    console.log('Recording started');
  } catch (err) {
    console.error('Failed to start recording', err);
    setMessage('录音启动失败：' + err.message);
  }
}

内容的提问来源于stack exchange，提问作者Pavel