settledIn/src/utils/newToExcel.js

import { isEmpty } from 'element-ui/lib/utils/util';
import ExcelJS from 'exceljs'
import * as FileSaver from 'file-saver'

export default function createWorkBook(header, title, data, foot, filename, sheets) {
  const letter = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'];
  let lcomun = 1;
  let worksheet;

  const workBook = new ExcelJS.Workbook();
  let long = header.length;

  /**
   *  创建工作薄
   * @param {*} sheets 
   */
  function createSheets(sheets) {
    let sheet = Array.isArray(sheets) ? sheets[0] : sheets;
    let style = Array.isArray(sheets) ? sheets[1] : {};
    worksheet = workBook.addWorksheet(sheet, style);
  }

  /**
   *  设置表名介绍等
   * @param {*} title 
   * @param {*} long 
   */
  function setTitle(title, long) {
    if (isEmpty(title)) return;
    title = Array.isArray(title) ? title : title.split(',');
    for (let i = 0; i < title.length; i++) {
      let ti = worksheet.getRow(i + 1);
      ti.getCell(1).value = title[i];
      ti.height = 30;
      ti.font = { bold: true, size: 20, vertAlign: 'subscript', };
      ti.alignment = { vertical: 'bottom', horizontal: 'center' };
      ti.outlineLevel = 1;
      worksheet.mergeCells(i + 1, 1, i + 1, long)
      ti.commit();
      lcomun++;
    }
  }
  /**
   *  设置表头行
   * @param {*} header 
   */
  function setHeader(header) {
    if (isEmpty(header)) return;
    const headerRow = worksheet.getRow(lcomun);
    for (let index = 1; index <= header.length; index++) {
      headerRow.getCell(index).value = header[index - 1];
    }
    headerRow.height = 25;
    headerRow.width = 50;
    headerRow.font = { bold: true, size: 18, vertAlign: 'subscript', };
    headerRow.alignment = { vertical: 'bottom', horizontal: 'center' };
    headerRow.outlineLevel = 1;
    headerRow.commit();
    lcomun++;
  }

  /**
   * 导出内容
   * @param {*} data 
   */
  function setContent(data) {
    if (isEmpty(data)) return;
    for (let h = 0; h < data.length; h++) {
      let satarLcomun = lcomun;
      let lcomunNow = worksheet.getRow(lcomun);
      let hasMerge = false;
      let starKey = 0;
      let endKey = 0;
      /** 循环列 */
      //需要操作第几列
      let sk = 0;
      for (let l = 0; l < data[h].length; l++) {
        if (Array.isArray(data[h][l])) {
          //数组长度
          starKey = sk;
          hasMerge = true;
          setArrayContent(data[h][l], sk);
          if (data[h][l][0]) {
            sk = sk + data[h][l][0].length
          }
          endKey = sk;
        } else {
          //不是数组
          lcomunNow.getCell(getLetter(sk)).value = data[h][l];
          lcomunNow.getCell(getLetter(sk)).border = { top: { style: 'thin' }, left: { style: 'thin' }, bottom: { style: 'thin' }, right: { style: 'thin' } };
          lcomunNow.alignment = { vertical: 'middle', horizontal: 'center' };
          sk++
        }
      }
      if (hasMerge) setMergeLcomun(satarLcomun, lcomun, starKey, endKey);
      lcomunNow.height = 25;
      lcomunNow.commit();
      lcomun++
    }
  }
  /**
   * 占多行的数组
   * @param {*} arr 
   * @param {*} sk 
   */
  function setArrayContent(arr, sk) {
    /**
     *  循环二维数组,在循环行  
     */
    let al = arr.length;
    let sl = al - 1;
    for (let i = 0; i < arr.length; i++) {
      let lcomunNow = worksheet.getRow(lcomun);
      for (let v = 0; v < arr[i].length; v++) {
        lcomunNow.getCell(getLetter(sk + v)).value = arr[i][v];
        lcomunNow.getCell(getLetter(sk + v)).border = { top: { style: 'thin' }, left: { style: 'thin' }, bottom: { style: 'thin' }, right: { style: 'thin' } };
        lcomunNow.alignment = { vertical: 'middle', horizontal: 'center' };
      }
      lcomunNow.height = 25;
      lcomunNow.commit()
      if (i < sl) lcomun++
    }
  }
  /**
   *  合并操作
   * @param {*} satarLcomun 
   * @param {*} endLcomun 
   * @param {*} starKey 
   * @param {*} endKey 
   */
  function setMergeLcomun(satarLcomun, endLcomun, starKey, endKey) {
    for (let ml = 0; ml < long; ml++) {
      if (ml < starKey || ml >= endKey) {
        worksheet.mergeCells(getLetter(ml) + satarLcomun + ':' + getLetter(ml) + endLcomun)
      }
    }
  }

  /**
   * 设置表末尾统计备注等
   * @param {*} footData 
   */
  function setFoot(footData) {
    if (isEmpty(footData)) return;
    if (Array.isArray(footData)) {
      for (let f = 0; f < footData.length; f++) {
        let lcomunNow = worksheet.getRow(lcomun);
        lcomunNow.getCell(1).value = footData[f];
        lcomunNow.getCell(1).border = { top: { style: 'thin' }, left: { style: 'thin' }, bottom: { style: 'thin' }, right: { style: 'thin' } };
        lcomunNow.alignment = { vertical: 'middle', horizontal: 'left' };
        worksheet.mergeCells('A' + lcomun + ':' + getLetter(long - 1) + lcomun)
        lcomun++
      }
    } else {
      let lcomunNow = worksheet.getRow(lcomun);
      lcomunNow.getCell(1).value = footData[f];
      lcomunNow.getCell(1).border = { top: { style: 'thin' }, left: { style: 'thin' }, bottom: { style: 'thin' }, right: { style: 'thin' } };
      lcomunNow.alignment = { vertical: 'middle', horizontal: 'left' };
      worksheet.mergeCells('A' + lcomun + ':' + getLetter(long - 1) + lcomun)
    }
  }

  /**
   *  处理超过26个字母的列
   * @param {*} number 
   * @returns 
   */
  function getLetter(number) {
    if (number < 26) {
      return letter[number];
    } else {
      let n = number % 26
      let l = Math.floor(number / 26) - 1
      return letter[l] + letter[n]
    }
  }

  /**
   *  导出下载
   * @param {*} filename 
   */
  function saveAndDowloade(filename) {
    if (!filename) filename = new Date().getTime();
    workBook.xlsx.writeBuffer().then(data => {
      const blob = new Blob([data], { type: 'application/octet-stream' })
      FileSaver.saveAs(blob, filename + '.xlsx')
    })
  }

  createSheets(sheets);
  setTitle(title, long);
  setHeader(header);
  setContent(data);
  setFoot(foot);
  saveAndDowloade(filename);

}