HarmonyOS 鸿蒙Next SaveButton保存图片授权失败

import photoAccessHelper from '@ohos.file.photoAccessHelper';
import fs from '@ohos.file.fs';
[@Entry](/user/Entry)
[@Component](/user/Component)
struct Index {
  build() {
    Row() {
      Column() {
        Image($r('app.media.product002'))
          .height(300)
          .width(300)
        SaveButton().onClick(async (event: ClickEvent, result: SaveButtonOnClickResult) => {
          if (result == SaveButtonOnClickResult.SUCCESS) {
            try {
              const context = getContext(this);
              let helper = photoAccessHelper.getPhotoAccessHelper(context);
              // onClick触发后5秒内通过createAsset接口创建图片文件，5秒后createAsset权限收回。
              let uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'jpg');
  // 使用uri打开文件，可以持续写入内容，写入过程不受时间限制
              let file = await fs.open(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
              try {
                context.resourceManager.getMediaContent($r('app.media.product002').id, 0)
                  .then(async value => {
                    let media = value.buffer;
                    // 写到媒体库文件中
                    await fs.write(file.fd, media);
                    await fs.close(file.fd);
                    AlertDialog.show({message:'已保存至相册!'});
                  });
              }
              catch (err) {
                console.error("error is "+ JSON.stringify(err))
              }
            } catch (error) {
              console.error("error is "+ JSON.stringify(error));
            }
          }
          else {
            AlertDialog.show({ message: "设置权限失败" })
          }
        })
      }
      .width('100%')
    }
    .height('100%') }
}<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>