JSON数据转EXCEL

JSON数据转EXCEL

前言

一、需要安装哪些依赖？

• npm install -S file-saver 用来生成文件的web应用程序
• npm install -S xlsx 电子表格格式的解析器

二、使用步骤

1.导入

代码如下（示例）：

import { saveAs } from 'file-saver'
import XLSX from 'xlsx/dist/xlsx.full.min'

2.封装的jsonToExcel函数

具体代码如下（示例）：

function datenum (v, date1904) {
  if (date1904) v += 1462
  let epoch = Date.parse(v)
  return (epoch - new Date(Date.UTC(1899, 11, 30))) / (24 * 60 * 60 * 1000)
}

function dataTows (data, w) {
  var ws = {
    s: {
      '!row': [{ wpx: 67 }]
    }
  }
  ws['!cols'] = []
  for (var n = 0; n !== data[0].length; ++n) {
    ws['!cols'].push({
      wpx: w[n]
    })
  }
  const range = { s: { c: 10000000, r: 10000000 }, e: { c: 0, r: 0 } }
  for (let R = 0; R !== data.length; ++R) {
    for (let C = 0; C !== data[R].length; ++C) {
      if (range.s.r > R) range.s.r = R
      if (range.s.c > C) range.s.c = C
      if (range.e.r < R) range.e.r = R
      if (range.e.c < C) range.e.c = C
      const cell = { v: data[R][C] }
      if (cell.v == null) continue
      const cellRef = XLSX.utils.encode_cell({ c: C, r: R })

      if (typeof cell.v === 'number') cell.t = 'n'
      else if (typeof cell.v === 'boolean') cell.t = 'b'
      else if (cell.v instanceof Date) {
        cell.t = 'n'
        cell.z = XLSX.SSF._table[14]
        cell.v = datenum(cell.v)
      } else cell.t = 's'

      ws[cellRef] = cell
    }
  }
  if (range.s.c < 10000000) ws['!ref'] = XLSX.utils.encode_range(range)
  return ws
}
function Workbook () {
  if (!(this instanceof Workbook)) return new Workbook()
  this.SheetNames = []
  this.Sheets = {}
}

function s2ab (s) {
  const buf = new ArrayBuffer(s.length)
  const view = new Uint8Array(buf)
  for (let i = 0; i !== s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF
  return buf
}

/*
 * th => 表头
 * data => 数据
 * fileName => 文件名
 * fileType => 文件类型
 * sheetName => sheet页名
 */
export default function toExcel ({ th, data, fileName, fileType, sheetName, w }) {
  data.unshift(th)
  const wb = new Workbook()
  const ws = dataTows(data, w)
  sheetName = sheetName || 'sheet1'
  wb.SheetNames.push(sheetName)
  wb.Sheets[sheetName] = ws
  fileType = fileType || 'xlsx'
  var wbout = XLSX.write(wb, { bookType: fileType, bookSST: false, type: 'binary' })
  fileName = fileName || '列表'
  saveAs(new Blob([s2ab(wbout)], { type: 'application/octet-stream' }), `${fileName}.${fileType}`)
}

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总结

jsonToExcel函数的封装是为了便于前端导出excel文件。