返回文件流下载附件

down.js
/**
 * @url 下载地址
 * @filename 所需要的文件名称
 */
import { getToken } from '@/utils/auth'
import { Message } from 'element-ui'
export function downFile(url, pre = false) {
  return new Promise((resolve, reject) => {
    const xhr = new XMLHttpRequest()
    const urls = process.env.VUE_APP_BASE_API + url
    xhr.open('GET', urls, true)
    xhr.setRequestHeader('Content-Type', `application/json`)
    xhr.setRequestHeader('Authorization', `${getToken()}`)
    xhr.responseType = 'blob'
    xhr.onload = () => {
      if (xhr.status === 200) {
        if (xhr.getResponseHeader('content-disposition') == null) {
          // 说明文件不存在
          Message({
            message: '导出失败',
            type: 'error',
            duration: 5 * 1000
          })
          reject(new Error('导出失败'))
        }
        const fileName = decodeURIComponent(xhr.getResponseHeader('content-disposition').split('fileName=')[1])
        if (window.navigator.msSaveOrOpenBlob) {
          navigator.msSaveBlob(xhr.response, fileName)
        } else {
          const body = document.querySelector('body')
          const imgurl = window.URL.createObjectURL(xhr.response)
          if (!pre) {
            const link = document.createElement('a')
            link.download = fileName
            link.href = imgurl
            link.style.display = 'none'
            body.appendChild(link)
            link.click()
            body.removeChild(link)
            window.URL.revokeObjectURL(link.href)
            Message({
              message: '下载成功！',
              type: 'success',
              duration: 5 * 1000
            })
            resolve({ data: '', msg: '下载成功！', state: xhr.statusText })
          } else {
            resolve({ data: imgurl, msg: '获取成功', state: xhr.statusText })
          }
        }
      } else {
        Message({
          message: xhr.statusText,
          type: 'error',
          duration: 5 * 1000
        })
        reject(new Error(xhr.statusText))
      }
    }
    xhr.send()
  })
}

　api.js

export function checkExcel(id) {
  return downFile(
    `/project/bid/checkExcel?id=${id}`
  )
}

 //返回url

    static downloadWithUrl(url: string) {
        const downloadUrl = this.getHost() + url;
        if (window.navigator && window.navigator.msSaveOrOpenBlob) {
            window.location.href = downloadUrl;
        } else {
            const link = document.createElement("a");
            link.style.display = "none";
            link.href = downloadUrl;
            document.body.appendChild(link);
            link.click();
            document.body.removeChild(link);
        }
    }