npm install --save xlsx file-saver

const FileSaver  = require("file-saver")

const XLSX   = require("xlsx")

var wb = XLSX.utils.table_to_book(document.querySelector("#tableBox"))

var wbout = XLSX.write(wb, { bookType: 'xlsx', bookSST: true, type: 'array' })

try {

  FileSaver.saveAs(new Blob([wbout], { type: 'application/octet-stream' }), 'sheetjs.xlsx')

} catch (e) { if (typeof console !== 'undefined') console.log(e, wbout) }

      // 执行下载

      async activeExportOut(){

        // this.ableExportOut = true //设置可以下载

        this.oldtableData = this.tableData //保存起就数据

        await this.setData()

        this.exportOut()

      },

      setData(){

        this.tableData = test //赋值新数据

      },

      //下载表格

      exportOut(){

         var wb = XLSX.utils.table_to_book(document.querySelector("#tableBox"))

         var wbout = XLSX.write(wb, { bookType: 'xlsx', bookSST: true, type: 'array' })

         try {

             FileSaver.saveAs(new Blob([wbout], { type: 'application/octet-stream' }), 'sheetjs.xlsx')

         } catch (e) { if (typeof console !== 'undefined') console.log(e, wbout) }

        //  this.ableExportOut = false //设置不可下载

         this.tableData = this.oldtableData //回复原来说的数据

         return wbout

      }