1.创建超链接，通过a标签的链接向后端服务发get请求，接收后端的文件流

<a :href='"/user/downloadExcel"' >下载模板</a>

2.创建iframe的方式

<el-button size="mini" type="text" icon="el-icon-download" @click="handleDownload(scope.row)">下载</el-button>
    /* 下载 */
    handleDownload(row) {
      this.loadingOverLay = this.$loading({
        lock: true,
        text: "文件生成中",
        spinner: "el-icon-loading",
        background: "rgba(0,0,0,0.7)",
      });
      var elemIF = document.createElement("iframe");
      elemIF.src = process.env.VUE_APP_BASE_API + "/transcode/download/" + row.id;
      elemIF.style.display = "none";
      document.body.appendChild(elemIF);
      this.loadingOverLay.close();
    },

3.对后端发的post请求，使用blob格式

<el-button  size="mini" class="filter-item" type="primary" icon="el-icon-download" @click="handleExport(scope.row)">导出</el-button>
//method方法
handleExport(row){
const url="/user/downloadExcel"
const options = {snapshotTime:formatDate(new Date(row.snapshotTime), 'yyyy-MM-dd hh:mm')}
exportExcel(url,options)
}
/**
 * 封装导出Excal文件请求
 * @param url
 * @param data
 * @returns {Promise}
 */
//api.js
export function exportExcel(url, options = {}) {
  return new Promise((resolve, reject) => {
    console.log(`${url} 请求数据，参数=>`, JSON.stringify(options))
    axios.defaults.headers['content-type'] = 'application/json;charset=UTF-8'
    axios({
      method: 'post',
      url: url, // 请求地址
      data: options, // 参数
      responseType: 'blob' // 表明返回服务器返回的数据类型
    }).then(
      response => {
        resolve(response.data)
        let blob = new Blob([response.data], {
          type: 'application/vnd.ms-excel'
        })
        console.log(blob)
        let fileName = Date.parse(new Date()) + '.xlsx'
        if (window.navigator.msSaveOrOpenBlob) {
          // console.log(2)
          navigator.msSaveBlob(blob, fileName)
        } else {
          // console.log(3)
          var link = document.createElement('a')
          link.href = window.URL.createObjectURL(blob)
          link.download = fileName
          link.click()
          //释放内存
          window.URL.revokeObjectURL(link.href)
        }
      },
      err => {
        reject(err)
      }
    )
  })
}

4.导出json文件

1.安装：npm install file-saver --save

2.引入：import FileSaver from 'file-saver'

/** 
 * data: 封装好的json数据 
 * JSON.stringify(data, null, 2): 格式化json数据 方便阅读
 * new Blob(parame1, parame2): 转为Blob文件流.
 * parame1 [] 数据源 
 * parame2 文件流类型
 */
const blob = new Blob([JSON.stringify(data, null, 2)], {type: 'application/json'})

/** 
 * FileSaver.saveAs(parame1, parame2)  浏览器保存文件
 * parame1: Blob文件流
 * parame2：文件名
 */
FileSaver.saveAs(blob, '文件名.json')