HarmonyOS excel文件如何打开

目前暂不支持excel文件的预览，可以通过downloadFile下载excel文件后通过应用文件分享的方式通过其他有应用打开excel文件，具体使用还请参考文档：

downloadFile：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-request-V5#requestdownloadfile9

应用文件分享：https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/share-app-file-V5

文件预览支持的文件类型：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/preview-arkts-V5

downloadSave() {
  let context = getContext(this) as common.UIAbilityContext;
  let filePath = context.filesDir + "/test.xlsx";
  let url = "excel文件的url"
  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}`);
  }
}