HarmonyOS鸿蒙Next中在弹窗中保存网络图片Permission denied, js errcode:201

HarmonyOS鸿蒙Next中在弹窗中保存网络图片Permission denied, js errcode:201

static async loadImageWithUrl(context:Context,url: string): Promise<boolean> {
    let pixelMaptemp: PixelMap | undefined = undefined;
    let responseCode = http.ResponseCode;
    let OutData: http.HttpResponse;
    let imagePackerApi = image.createImagePacker();
    let packOpts: image.PackingOption = { format: 'image/jpeg', quality: 100 };
    // 确保网络正常
    http.createHttp().request(url, {
      method: http.RequestMethod.GET,
      connectTimeout: 60000,
      readTimeout: 60000
    },
      async (error: BusinessError, data: http.HttpResponse) => {
        if (error) {
          console.error(`http request failed with. Code: ${error.code}, message: ${error.message}`);
        } else {
          OutData = data;
          let code: http.ResponseCode | number = OutData.responseCode;
          if (responseCode.OK === code) {
            let imageData: ArrayBuffer = OutData.result as ArrayBuffer;
            let imageSource: image.ImageSource = image.createImageSource(imageData);

            class tmp {
              height: number = 100
              width: number = 100
            };

            let options: Record<string, number | boolean | tmp> = {
              'alphaType': 0, // Transparency
              'editable': false, // Is it editable
              'pixelFormat': 3, // Pixel Format
              'scaleMode': 1, // Abbreviation
              'size': { height: 100, width: 100 }
            }; // Create Image Size
            imageSource.createPixelMap(options).then((pixelMap: PixelMap) => {
              pixelMaptemp = pixelMap;
              pixelMaptemp.getImageInfo().then((info: image.ImageInfo) => {
                console.info('info.width = ' + info.size.width);
              }).catch((err: BusinessError) => {
                console.error('Failed ' + err);
              })
              imagePackerApi.packToData(pixelMaptemp, packOpts).then(async (buffer: ArrayBuffer) => {
                try {
                  let helper = photoAccessHelper.getPhotoAccessHelper(context);
                  let uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'png');
                  let file = await fs.open(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
                  // Write to file
                  await fs.write(file.fd, buffer);
                  promptAction.openToast({
                    message: '已保存至相册',
                    duration: 2500
                  });
                  // Close the file
                  await fs.close(file.fd);
                } catch (error) {
                  console.error('error is ' + JSON.stringify(error));
                }
                return false
              }).catch((error: BusinessError) => {
                console.error('Failed to pack the image. And the error is: ' + error);
              }).finally(()=>{
                pixelMap.release();
              })

            })
          }
        }
      }
    )
    return false
  }

以上是保存图片的方法

@CustomDialog
@Component
struct CustomDialogExample {
  @Prop smallPic: string;
  @Prop bigPic: string;
  @Prop context: Context;
  controller?: CustomDialogController;
  build() {
    Stack({ alignContent: Alignment.Bottom }) {
      Image(this.smallPic)
        .width('100%')
        .height("100%")
      Button("保存到相册", { type: ButtonType.Normal, stateEffect: true })
        .onClick(async ()=>{
          await FilesUtils.loadImageWithUrl(this.context,this.bigPic).then((result)=>{
            if (result) {
              this.controller?.close()
            }
          });
        })
        .borderRadius(8)
        .backgroundColor(0x317aff)
    }.borderRadius(10).height(300)
  }
}

以上是弹窗代码

dialogController: CustomDialogController | null = new CustomDialogController({
    builder: CustomDialogExample({
      smallPic: this.datepicBean[0].smallPic,
      bigPic: this.datepicBean[0].bigPic,
      context:this.context
    }),
    autoCancel: true,
    onWillDismiss: (dismissDialogAction: DismissDialogAction) => {
      console.info(`reason= ${dismissDialogAction.reason}`);
      console.info('dialog onWillDismiss');
      if (dismissDialogAction.reason == DismissReason.PRESS_BACK) {
        dismissDialogAction.dismiss();
      }
      if (dismissDialogAction.reason == DismissReason.TOUCH_OUTSIDE) {
        dismissDialogAction.dismiss();
      }
    },
    alignment: DialogAlignment.Bottom,
    offset: { dx: 0, dy: -20 },
    gridCount: 4,
    customStyle: false,
    cornerRadius: 10,
  })

以上是弹窗Controller，context为：

private context = this.getUIContext().getHostContext()!;

现在是在弹窗中保存图片就提示Permission denied, js errcode:201，如果不在弹窗中调用loadImageWithUrl就能正常保存图片，请问这个context该怎么传？