axios + vue导出excel文件

（使用到了elementUI框架）

<template>
    <el-button type="primary" size="mini" @click="exportExcel">导出</el-button>
</template>
<script>
    import API from '../api/api_dispatch'
    export default {
        data() {
            return {
                myCompanyId: ''
            }
        },
        created() {
            let userInfo = JSON.parse(window.sessionStorage.getItem('access-user'));
            this.myCompanyId = userInfo.companyId;
        },
        methods: {
            exportExcel() {
                // 按需要可加上无数据不导出的判断（略）
                if (this.myCompanyId !== '') {
                    API.exportExcel({
                        companyId: this.myCompanyId
                    }).then(res => {
                        var blob = new Blob([res], {type: 'application/vnd.ms-excel;charset=utf-8'})
                        var downloadElement = document.createElement('a');
                        var href = window.URL.createObjectURL(blob); //创建下载的链接
                        downloadElement.href = href;
                        downloadElement.download = '导出文件.xls'; //下载后文件名
                        document.body.appendChild(downloadElement);
                        downloadElement.click(); //点击下载
                        document.body.removeChild(downloadElement); //下载完成移除元素
                        window.URL.revokeObjectURL(href); //释放掉blob对象
                    });
                } else {
                    this.$message.error('操作异常');
                }
            }
        }
    }
</script>

api/api_dispatch.js:

import * as API from './'

export default {
    // 导出报表
    exportExcel: params => {
        return API.EXPORT('outOfDate/excel/export', params);
    }
}

api/index.js:（省略了其他的GET、POST等方法）

import Env from './env'; // 声明接口地址文件
import axios from 'axios'

//基地址
let base = Env.baseURL;
let instance = axios.create({
    responseType: 'blob', //返回数据的格式，可选值为arraybuffer,blob,document,json,text,stream，默认值为json
})
// instance 添加一个请求拦截器
instance.interceptors.request.use(function (config) {
    let user = JSON.parse(window.sessionStorage.getItem('access-user'));
    config.headers.common['token'] = user.token
    return config;
}, function (error) {
    // Do something with request error
    console.info("error: ");
    console.info(error);
    return Promise.reject(error);
})

// 导出
export const EXPORT = (url, params) => {
    return instance({
        method: 'get',
        url: `${base}` + url,
        params: params
    }).then(res => {
        return Promise.resolve(res.data)
    })
}