1. 单个附件下载

<el-button
      type="text"
      size="small"
      @click.native.prevent="download(scope.row)" >下载</el-button>


export default {
    data() {
        return {
            downloadUrl: 'http://127.0.0.1:8881/XX/XX', // 下载接口
        }
    },
    methods: {
        download(row) { // 单个附件下载
              // 下载附件（form方式）
          const params = {
            fileId: row.dataId,
            fileName: row.fileName,
            attachmentId: row.dataId,
            token: getToken()
          }
          this.postDownloadFile(params, this.downloadUrl)

          // downloadFileByToken({ attachmentId: row.dataId }).then((response) => { // 按钮提交无效
          // })
    },
    postDownloadFile(params, url) {
          const form = document.createElement('form')
          form.style.display = 'none'
          form.action = url
          form.method = 'post'
          document.body.appendChild(form)
          // 动态创建input并给value赋值
          for (const key in params) {
            const input = document.createElement('input')
            input.type = 'hidden'
            input.name = key
            input.value = params[key]
            form.appendChild(input)
          }
          form.submit()
          form.remove() 
        },
    },
}

灵感来自：https://blog.csdn.net/ewl0116/article/details/129879216