HarmonyOS 如何获取系统相册的数据

读取相册中的图片可参考如下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;
  // @State img:ImageSource = $r('app.media.app_icon')
  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];
    // 读取图片为buffer
    const file = fs.openSync(this.albumPath, fs.OpenMode.READ_WRITE);
    this.photoSize = fs.statSync(file.fd).size;
    console.info('Photo Size: ' + this.photoSize);
    let buffer = new ArrayBuffer(this.photoSize);
    fs.readSync(file.fd, buffer);
    fs.closeSync(file);

    // 解码成PixelMap
    const imageSource = image.createImageSource(buffer);
    console.log('imageSource: ' + JSON.stringify(imageSource));
    this.pixel = await imageSource.createPixelMap({});

  }
  build() {
    Row() {
      Column() {
        Image(this.pixel)
          .width('100%')
          .aspectRatio(1)
        Button('显示照片')
          .onClick(()=>{
            this.getPictureFromAlbum()
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}

通过使用photoAccessHelper.PhotoSelectOptions接口，详细可参考上述链接使用Picker选择媒体库资源：

https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/photoaccesshelper-resource-guidelines-V5#%E4%BD%BF%E7%94%A8%E5%AE%89%E5%85%A8%E6%8E%A7%E4%BB%B6%E5%88%9B%E5%BB%BA%E5%AA%92%E4%BD%93%E8%B5%84%E6%BA%90

https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/photoaccesshelper-systemalbum-guidelines-V5