vue axios下载excel时获取不到返回的消息头Content-Disposition

参考：https://wwwblogs/smiler/p/8708815.html

vue的axios下载excel时，获取不到Content-Disposition内容，提取文件名

function postDownload(downloadUrl, params, contentType, callback){
  let headers = {
      'Content-Type': contentType
    };
  axios(
    {
      method: "post",
      url: downloadUrl,
      data: params,
      headers: headers,
      responseType: "blob",    // 指定获取数据的类型为blob
    }
  ).then(
    function (response) {
      console.log(response);
      // 前提是服务端要在header设置Access-Control-Expose-Headers: Content-Disposition
      // 前端才能正常获取到Content-Disposition内容
      const disposition = response.headers['content-disposition'];
      let fileName = disposition.substring(disposition.indexOf('filename=') + 9, disposition.length);
      // iso8859-1的字符转换成中文
      fileName = decodeURI(escape(fileName));
      // 去掉双引号
      fileName = fileName.replace(/\"/g, "");
      const content = response.data;
      console.info("rep:", disposition);
      console.info("fileName:", fileName);
      // 创建a标签并点击， 即触发下载
      let url = window.URL.createObjectURL(new Blob([content]));
      let link = document.createElement("a");
      link.style.display = "none";
      link.href = url;
      link.setAttribute("download", fileName);
      //link.download = "测试下载文件.xls"
      // 模拟
      document.body.appendChild(link);
      link.click();
      // 释放URL 对象
      window.URL.revokeObjectURL(link.href);
      document.body.removeChild(link)
    }
  ).catch(function (err) {
    console.log(err)
  })
}

这个语句获取不到

const disposition = response.headers['content-disposition'];

最后找到了解决方法：
只需要在服务器端返回response的header里面设置

Access-Control-Expose-Headers: Content-Disposition