HarmonyOS 相册选择视频后, 获取的视频缩略图展示不了

最后的pixelMap展示不出。

let phAccessHelper = photoAccessHelper.getPhotoAccessHelper(getContext(this))
let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
// 配置查询条件，使用PhotoViewPicker选择图片返回的uri进行查询
predicates.equalTo('uri', uri);
let fetchOption: photoAccessHelper.FetchOptions = {
  fetchColumns: [photoAccessHelper.PhotoKeys.WIDTH, photoAccessHelper.PhotoKeys.HEIGHT, photoAccessHelper.PhotoKeys.TITLE, photoAccessHelper.PhotoKeys.DURATION],
  predicates: predicates
};
let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
// 得到uri对应的PhotoAsset对象，读取文件的部分信息
const asset: photoAccessHelper.PhotoAsset = await fetchResult.getFirstObject();
// 获取缩略图
const pixelMap = await asset.getThumbnail({width: w, height: h})
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HarmonyOS

aquaa

2024-12-25 17:00:08

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回答 1

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zxjiu

更简单的获取缩率图场景，使用avImageGenerator。https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/avimagegenerator-V5#完整示例

@Component
export struct PhotoPickerThPage {
  @State pix: PixelMap | undefined = undefined;

  aboutToAppear(): void {
  }

  build() {
    Stack() {
      Button("拉起 picker 并写入系统相册")
        .onClick(async () => {
          let avImageGenerator: media.AVImageGenerator = await media.createAVImageGenerator();
          let timeUs = 0;
          let queryOption = media.AVImageQueryOptions.AV_IMAGE_QUERY_NEXT_SYNC;
          let param: media.PixelMapParams = {};
          let options = new photoAccessHelper.PhotoSelectOptions();
          options.MIMEType = photoAccessHelper.PhotoViewMIMETypes.VIDEO_TYPE;
          let photoPicker = new photoAccessHelper.PhotoViewPicker();
          // 获取图片结果
          let res: picker.PhotoSelectResult = await photoPicker.select(options);
          try {
            let file = fileIo.openSync(res.photoUris[0], fileIo.OpenMode.READ_ONLY);
            avImageGenerator.fdSrc = {fd: file.fd};
            // 获取缩略图
            this.pix = await avImageGenerator.fetchFrameByTime(timeUs, queryOption, param);
          } catch (e) {
            let err = e as BusinessError
            console.error(err.message)
          }
        })
    }.height("100%")
    .width("100%")
  }
}
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2024-12-25 19:17:52

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HarmonyOS 相册选择视频后, 获取的视频缩略图展示不了

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