HarmonyOS 鸿蒙Next webview 中h5 保存网络图片到相册 下载excel格式的文件需要调用什么方法

当前下载保存可以参考以下demo：

// 下载保存

  downloadSave() {

    let context = GlobalContext.getContext().getObject("UIAbilityContext") as common.UIAbilityContext

    let filePath = context.filesDir + "/test5.xlsx";

    let url = "http://****YdExcel/20240605173655470PC%E8%BF%90%E5%8D%95%E7%AE%A1%E7%90%86.xlsx"

    try {

      request.downloadFile(context, { url: url, filePath: filePath }).then((data: request.DownloadTask) => {

        let downloadTask: request.DownloadTask = data;

        downloadTask.on('complete', () => {

          console.info('download complete');

          let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);

          let arrayBuffer = new ArrayBuffer(4096000);

          let readLen = fs.readSync(file.fd, arrayBuffer);

          let buf = buffer.from(arrayBuffer, 0, readLen);

          console.info(`content of File: ${buf.toString()}`);

          let writeLen = fs.writeSync(file.fd, arrayBuffer);

          fs.closeSync(file);

          const documentSaveOptions = new picker.DocumentSaveOptions();

          // 创建文件管理器选项实例

          documentSaveOptions.newFileNames = ["1.xlsx"];

          // 保存文件名（可选）

          documentSaveOptions.fileSuffixChoices = ['xlsx'];

          // 保存文件类型（可选）

          let uris: Array<string> = [];

          const documentViewPicker = new picker.DocumentViewPicker();

          // 创建文件选择器实例

          documentViewPicker.save(documentSaveOptions).then((documentSaveResult: Array<string>) => {

            uris = documentSaveResult;

            console.info('documentViewPicker.save to file succeed and uris are:' + uris);

            let uri = uris[0];

            let file2 = fs.openSync(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);

            let writeLen2 = fs.writeSync(file2.fd, arrayBuffer);

            fs.closeSync(file2);

          }).catch((err: BusinessError) => {

            console.error(`Invoke documentViewPicker.save failed, code is ${err.code}, message is ${err.message}`);

          })

        })

        let failCallback = () => {

          console.info('Download task fail.');

        };

        downloadTask.on('fail', failCallback);

      }).catch((err: BusinessError) => {

        console.error(`downLoadFileTask failed, code is ${err.code}, message is ${err.message}`);

      });

    } catch (error) {

      console.error(`downLoadFileTask failed, code is ${error.code}, message is ${error.message}`);

    }

  }