HarmonyOS 鸿蒙Next怎样将 【相册中选中】或【相机拍摄】的图片转成Base64编码呢？

将沙盒中的图片生成PixelMap

export async function generatePixelMapWithImagePath(imgPath: string): Promise<image.PixelMap> {
  const imageSource: image.ImageSource = image.createImageSource(imgPath);
  let decodingOptions: image.DecodingOptions = {
    editable: true,
    desiredPixelFormat: 3,
  };
  try {
    const gPixelMap = await imageSource.createPixelMap(decodingOptions);
    console.log("Succeeded in creating PixelMap = ", gPixelMap);
    return gPixelMap;
  } catch (error) {
    console.error("Failed to create PixelMap");
    return Promise.reject(error);
  }
}

将指定的PixelMap转化为ArrayBuffer

export async function encodePixelMap2ImageArrayBuffer(aPixelMap:image.PixelMap): Promise<ArrayBuffer> {
  const imagePackerApi = image.createImagePacker();
  let packOpts: image.PackingOption = { format: "image/jpeg", quality: 80 };
  try {
    let data = await imagePackerApi.packing(aPixelMap, packOpts);
    console.info("PixelMap 2 ArrayBuffer = ", data.byteLength.toString());
    return data;
  } catch (error) {
    console.error('Failed to pack the image. And the error is: ' + JSON.stringify(error));
    return Promise.reject(error);
  }
}

export async function imageDataArrayBuffer2Base64(buf: ArrayBuffer, cardSide: number): Promise<string> { try { let array = new Uint8Array(buf.slice(0, buf.byteLength)); let result = new util.Base64Helper().encodeToStringSync(array, util.Type.MIME); return result; } catch (error) { console.info('born base64Str with error = ', JSON.stringify(error)); return Promise.reject(error); } }

我这边也解决了，你这个有点麻烦

filePath：沙河路径，type：图片类型

```javascript
static  imageFileToBase64(filePath:string,type:string) : string{
    let file = fs.openSync(filePath, fs.OpenMode.READ_ONLY);
    let stats = fs.statSync(file.fd)
    console.log('message file.fd = %ld', file.fd)
    console.log('message file.fd = %ld', stats.size)
    let buffer = new ArrayBuffer(stats.size)
    let readLen = fs.readSync(file.fd, buffer);
    console.info('readSync data to file succeed and buffer size is:' + readLen);
    fs.closeSync(file);
    let that = new util.Base64Helper();
    let array = new Uint8Array(buffer);
    let base64 = `data:image/${type};base64,` + that.encodeToStringSync(array,util.Type.BASIC);
    return base64
}