umi-request获取content-disposition

后端将文件流的名称放在了content-disposition，需要自己取出文件名称，代码如下

request(url, {
    method: 'POST',
    body: JSON.stringify(params),
    responseType: 'blob',
    getResponse: true   // 重点
  });

//导出
 onExport = () => {
    const { dispatch } = this.props;
    let filename = ``;
    dispatch({
      type: 'xxx/onExport',
    })
      .then((res) => {
        const disposition = res.response.headers.get('content-disposition');
        filename = disposition
          ? decodeURI(disposition.split(';')[1].split("filename*=utf-8''")[1])
          :null;
        return res.data;
      })
      .then((res) => {
        Modal.destroyAll();
        let reader = new FileReader();
        reader.readAsText(res);
        reader.onload = function (result) {
          try {
            let resData = JSON.parse(result.target.result);
            if (resData && resData.status !== 100) {
              Modal.error({
                title: '出错啦～',
                content: resData.message || '下载失败',
              });
            }
          } catch (err) {
            if (!res.size) {
              message.error('下载失败');
              return false;
            }
            // 解析成对象失败，说明是正常的文件流
            const blobUrl = window.URL.createObjectURL(res);
            let clickElm = document.createElement('a');
            clickElm.href = blobUrl;
            clickElm.download = filename || `报表xxx.xlsx`;
            clickElm.click();
            window.URL.revokeObjectURL(blobUrl);
            message.success('导出成功');
          }
        };
      });
  };