将后台返回的文件流转成文件下载

// 安装file-saver插件
npm install file-saver --save

import * as FileSaver from 'file-saver';


let blob = new Blob([ 后台返回的excel的文件流数据 ], {
            type: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-16le"
        });
FileSaver.saveAs(blob, "export.xls");