HarmonyOS NEXT鸿蒙开发：将 AudioCapturer 录音封装成工具类-马育民老师

# 介绍

[官方介绍](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/using-audiocapturer-for-recording-V5 "官方介绍")

将 `AudioCapturer` 录音代码，进行封装

# 代码

### 创建目录

在 `ets` 创建目录 `utils`

### 创建文件

在 `utils` 目录下创建 `AudioCapturerUtil.ets` 文件，内容如下：

```
import { audio } from '@kit.AudioKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { fileIo as fs } from '@kit.CoreFileKit';

const TAG = 'AudioCapturerUtils--------';

class Options {
  offset?: number;
  length?: number;
}

let bufferSize: number = 0;
let audioCapturer: audio.AudioCapturer | undefined = undefined;
let audioStreamInfo: audio.AudioStreamInfo = {
  samplingRate: audio.AudioSamplingRate.SAMPLE_RATE_48000, // 采样率
  channels: audio.AudioChannel.CHANNEL_2, // 通道
  sampleFormat: audio.AudioSampleFormat.SAMPLE_FORMAT_S16LE, // 采样格式
  encodingType: audio.AudioEncodingType.ENCODING_TYPE_RAW // 编码格式
};
let audioCapturerInfo: audio.AudioCapturerInfo = {
  source: audio.SourceType.SOURCE_TYPE_MIC, // 音源类型
  capturerFlags: 0 // 音频采集器标志
};
let audioCapturerOptions: audio.AudioCapturerOptions = {
  streamInfo: audioStreamInfo,
  capturerInfo: audioCapturerInfo
};
let path = getContext().cacheDir;
let filePath = path + '/StarWars10s-2C-48000-4SW.pcm';
let file: fs.File = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
let readDataCallback = (buffer: ArrayBuffer) => {
  let options: Options = {
    offset: bufferSize,
    length: buffer.byteLength
  }
  fs.writeSync(file.fd, buffer, options);
  bufferSize += buffer.byteLength;
};

// 初始化，创建实例，设置监听事件
export function init() {
  console.log(`${TAG}`,"init()")
  audio.createAudioCapturer(audioCapturerOptions, (err, capturer) => { // 创建AudioCapturer实例
    if (err) {
      console.error(`${TAG}`,`Invoke createAudioCapturer failed, code is ${err.code}, message is ${err.message}`);
      return;
    }
    console.info(`${TAG}: create AudioCapturer success`);
    audioCapturer = capturer;
    if (audioCapturer !== undefined) {
      (audioCapturer as audio.AudioCapturer).on('readData', readDataCallback);
    }
  });
}

// 开始一次音频采集
export function start() {
  console.log(`${TAG}`,"start()")
  if (audioCapturer !== undefined) {
    let stateGroup = [audio.AudioState.STATE_PREPARED, audio.AudioState.STATE_PAUSED, audio.AudioState.STATE_STOPPED];
    if (stateGroup.indexOf((audioCapturer as audio.AudioCapturer).state.valueOf()) === -1) { // 当且仅当状态为STATE_PREPARED、STATE_PAUSED和STATE_STOPPED之一时才能启动采集
      console.error(`${TAG}: start failed`);
      return;
    }

// 启动采集
    (audioCapturer as audio.AudioCapturer).start((err: BusinessError) => {
      if (err) {
        console.error('Capturer start failed.');
      } else {
        console.info('Capturer start success.');
      }
    });
  }
}

// 停止采集
export function stop() {
  console.log(`${TAG}`,"stop()")
  if (audioCapturer !== undefined) {
    // 只有采集器状态为STATE_RUNNING或STATE_PAUSED的时候才可以停止
    if ((audioCapturer as audio.AudioCapturer).state.valueOf() !== audio.AudioState.STATE_RUNNING && (audioCapturer as audio.AudioCapturer).state.valueOf() !== audio.AudioState.STATE_PAUSED) {
      console.info('Capturer is not running or paused');
      return;
    }

//停止采集
    (audioCapturer as audio.AudioCapturer).stop((err: BusinessError) => {
      if (err) {
        console.error('Capturer stop failed.');
      } else {
        fs.close(file);
        console.info('Capturer stop success.');
      }
    });
  }
}

// 销毁实例，释放资源
export function release() {
  console.log(`${TAG}`,"release()")
  if (audioCapturer !== undefined) {
    // 采集器状态不是STATE_RELEASED或STATE_NEW状态，才能release
    if ((audioCapturer as audio.AudioCapturer).state.valueOf() === audio.AudioState.STATE_RELEASED || (audioCapturer as audio.AudioCapturer).state.valueOf() === audio.AudioState.STATE_NEW) {
      console.info('Capturer already released');
      return;
    }

//释放资源
    (audioCapturer as audio.AudioCapturer).release((err: BusinessError) => {
      if (err) {
        console.error('Capturer release failed.');
      } else {
        console.info('Capturer release success.');
      }
    });
  }
}

/**
 * 获取录音文件
 * @returns
 */
export function getFilePath():string{
  return filePath;
}
```

# 使用

[HarmonyOS NEXT鸿蒙开发：使用 AudioCapturer 录音（PCM 格式）](https://www.malaoshi.top/show_1GW2O8GGAVXW.html "HarmonyOS NEXT鸿蒙开发：使用 AudioCapturer 录音（PCM 格式）")

原文出处：http://www.malaoshi.top/show_1GW2O7ugzjlb.html