HarmonyOS 相册选择的文件路径如何转成ArrayBuffer

可以参考以下demo：

import photoAccessHelper from '@ohos.file.photoAccessHelper';
import image from '@ohos.multimedia.image';
import fs from '@ohos.file.fs';

@Entry
@Component
struct Index {
  @State getAlbum: string = '显示相册中的图片';
  @State pixel: image.PixelMap | undefined = undefined;
  @State albumPath: string = ''
  @State photoSize: number = 0;

  async getPictureFromAlbum() {
    //拉起相册，选择图片
    let PhotoSelectOptions = new photoAccessHelper.PhotoSelectOptions;
    PhotoSelectOptions.MIMEType = photoAccessHelper.PhotoViewMIMETypes.IMAGE_TYPE;
    PhotoSelectOptions.maxSelectNumber = 1;
    let photoPicker = new photoAccessHelper.PhotoViewPicker();
    let photoSelectResult: photoAccessHelper.PhotoSelectResult = await photoPicker.select(PhotoSelectOptions);
    this.albumPath = photoSelectResult.photoUris[0];
    1
    //读取图片为buffer
    const file = fs.openSync(this.albumPath, fs.OpenMode.READ_WRITE);
    this.photoSize = fs.statSync(file.fd).size;
    let buffer = new ArrayBuffer(this.photoSize);
    fs.readSync(file.fd, buffer);
    fs.closeSync(file);
    //解码成PixelMap
    const imageSource = image.createImageSource(buffer);
    this.pixel = await imageSource.createPixelMap({});
  }

  build() {
    Row() {
      Column() {
        Button(this.getAlbum)
          .onClick(() => {
            this.getPictureFromAlbum()
          })
        Image(this.pixel)
          .objectFit(ImageFit.None)
      }
      .width('100%')
    }
    .height('100%')
  }
}
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