Vue 使用 Export2Excel.js 导出多 sheet 的 excel

项目需求，导出多sheet的excel表格。
具体思路是：后端返回json数据，前端根据数据和具体的几项字段去导出excel表格，多sheet，多页表格到一个excel表里面，具体思路根据Export2Excel插件，并修改插件Export2Excel完成导出多页(多个sheet)的excel

真实项目使用

1、安装依赖（插件）

npm install file-saver --save
npm install xlsx --save
npm install script-loader --save-dev

2、下载两个所需要的js文件Blob.js和 Export2Excel.js。

Blob.js文件(utils/Blob.js)

/* eslint-disable */
/* Blob.js
 * A Blob implementation.
 * 2014-05-27
 *
 * By Eli Grey, http://eligrey.com
 * By Devin Samarin, https://github.com/eboyjr
 * License: X11/MIT
 *   See LICENSE.md
 */
 
/*global self, unescape */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
 plusplus: true */
 
/*! @source http://purl.eligrey.com/github/Blob.js/blob/master/Blob.js */
 
(function (view) {
 
  "use strict";

  view.URL = view.URL || view.webkitURL;

  if (view.Blob && view.URL) {
    try {
      new Blob;
      return;
    } catch (e) {}
  }

  // Internally we use a BlobBuilder implementation to base Blob off of
  // in order to support older browsers that only have BlobBuilder
  var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || (function(view) {
    var
      get_class = function(object) {
        return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
      }
      , FakeBlobBuilder = function BlobBuilder() {
        this.data = [];
      }
      , FakeBlob = function Blob(data, type, encoding) {
        this.data = data;
        this.size = data.length;
        this.type = type;
        this.encoding = encoding;
      }
      , FBB_proto = FakeBlobBuilder.prototype
      , FB_proto = FakeBlob.prototype
      , FileReaderSync = view.FileReaderSync
      , FileException = function(type) {
        this.code = this[this.name = type];
      }
      , file_ex_codes = (
        "NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR "
        + "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
      ).split(" ")
      , file_ex_code = file_ex_codes.length
      , real_URL = view.URL || view.webkitURL || view
      , real_create_object_URL = real_URL.createObjectURL
      , real_revoke_object_URL = real_URL.revokeObjectURL
      , URL = real_URL
      , btoa = view.btoa
      , atob = view.atob

      , ArrayBuffer = view.ArrayBuffer
      , Uint8Array = view.Uint8Array
    ;
    FakeBlob.fake = FB_proto.fake = true;
    while (file_ex_code--) {
      FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
    }
    if (!real_URL.createObjectURL) {
      URL = view.URL = {};
    }
    URL.createObjectURL = function(blob) {
      var
        type = blob.type
        , data_URI_header
      ;
      if (type === null) {
        type = "application/octet-stream";
      }
      if (blob instanceof FakeBlob) {
        data_URI_header = "data:" + type;
        if (blob.encoding === "base64") {
          return data_URI_header + ";base64," + blob.data;
        } else if (blob.encoding === "URI") {
          return data_URI_header + "," + decodeURIComponent(blob.data);
        } if (btoa) {
          return data_URI_header + ";base64," + btoa(blob.data);
        } else {
          return data_URI_header + "," + encodeURIComponent(blob.data);
        }
      } else if (real_create_object_URL) {
        return real_create_object_URL.call(real_URL, blob);
      }
    };
    URL.revokeObjectURL = function(object_URL) {
      if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) {
        real_revoke_object_URL.call(real_URL, object_URL);
      }
    };
    FBB_proto.append = function(data/*, endings*/) {
      var bb = this.data;
      // decode data to a binary string
      if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
        var
          str = ""
          , buf = new Uint8Array(data)
          , i = 0
          , buf_len = buf.length
        ;
        for (; i < buf_len; i++) {
          str += String.fromCharCode(buf[i]);
        }
        bb.push(str);
      } else if (get_class(data) === "Blob" || get_class(data) === "File") {
        if (FileReaderSync) {
          var fr = new FileReaderSync;
          bb.push(fr.readAsBinaryString(data));
        } else {
          // async FileReader won't work as BlobBuilder is sync
          throw new FileException("NOT_READABLE_ERR");
        }
      } else if (data instanceof FakeBlob) {
        if (data.encoding === "base64" && atob) {
          bb.push(atob(data.data));
        } else if (data.encoding === "URI") {
          bb.push(decodeURIComponent(data.data));
        } else if (data.encoding === "raw") {
          bb.push(data.data);
        }
      } else {
        if (typeof data !== "string") {
          data += ""; // convert unsupported types to strings
        }
        // decode UTF-16 to binary string
        bb.push(unescape(encodeURIComponent(data)));
      }
    };
    FBB_proto.getBlob = function(type) {
      if (!arguments.length) {
        type = null;
      }
      return new FakeBlob(this.data.join(""), type, "raw");
    };
    FBB_proto.toString = function() {
      return "[object BlobBuilder]";
    };
    FB_proto.slice = function(start, end, type) {
      var args = arguments.length;
      if (args < 3) {
        type = null;
      }
      return new FakeBlob(
        this.data.slice(start, args > 1 ? end : this.data.length)
        , type
        , this.encoding
      );
    };
    FB_proto.toString = function() {
      return "[object Blob]";
    };
    FB_proto.close = function() {
      this.size = this.data.length = 0;
    };
    return FakeBlobBuilder;
  }(view));

  view.Blob = function Blob(blobParts, options) {
    var type = options ? (options.type || "") : "";
    var builder = new BlobBuilder();
    if (blobParts) {
      for (var i = 0, len = blobParts.length; i < len; i++) {
        builder.append(blobParts[i]);
      }
    }
    return builder.getBlob(type);
  };
}(typeof self !== "undefined" && self || typeof window !== "undefined" && window || this.content || this));

Export2Excel.js文件(utils/Export2Excel.js)
修改过的 Export2Excel.js 主要修改 export_json_to_excel 函数

//Export2Excel.js 
 
/* eslint-disable */
require("script-loader!file-saver")
// import XLSX from "xlsx"
import * as XLSX from 'xlsx';  // 使用这个方法引入防止报错

function generateArray(table) {
  var out = []
  var rows = table.querySelectorAll("tr")
  var ranges = []
  for (var R = 0; R < rows.length; ++R) {
    var outRow = []
    var row = rows[R]
    var columns = row.querySelectorAll("td")
    for (var C = 0; C < columns.length; ++C) {
      var cell = columns[C]
      var colspan = cell.getAttribute("colspan")
      var rowspan = cell.getAttribute("rowspan")
      var cellValue = cell.innerText
      if (cellValue !== "" && cellValue == +cellValue) cellValue = +cellValue
 
      //Skip ranges
      ranges.forEach(function(range) {
        if (
          R >= range.s.r &&
          R <= range.e.r &&
          outRow.length >= range.s.c &&
          outRow.length <= range.e.c
        ) {
          for (var i = 0; i <= range.e.c - range.s.c; ++i) outRow.push(null)
        }
      })
 
      //Handle Row Span
      if (rowspan || colspan) {
        rowspan = rowspan || 1
        colspan = colspan || 1
        ranges.push({
          s: {
            r: R,
            c: outRow.length
          },
          e: {
            r: R + rowspan - 1,
            c: outRow.length + colspan - 1
          }
        })
      }
 
      //Handle Value
      outRow.push(cellValue !== "" ? cellValue : null)
 
      //Handle Colspan
      if (colspan) for (var k = 0; k < colspan - 1; ++k) outRow.push(null)
    }
    out.push(outRow)
  }
  return [out, ranges]
}
 
function datenum(v, date1904) {
  if (date1904) v += 1462
  var epoch = Date.parse(v)
  return (epoch - new Date(Date.UTC(1899, 11, 30))) / (24 * 60 * 60 * 1000)
}
 
function sheet_from_array_of_arrays(data, opts) {
  var ws = {}
  var range = {
    s: {
      c: 10000000,
      r: 10000000
    },
    e: {
      c: 0,
      r: 0
    }
  }
  for (var R = 0; R != data.length; ++R) {
    for (var 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
      var cell = {
        v: data[R][C]
      }
      if (cell.v == null) continue
      var cell_ref = 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[cell_ref] = 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) {
  var buf = new ArrayBuffer(s.length)
  var view = new Uint8Array(buf)
  for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xff
  return buf
}
 
export function export_table_to_excel(id) {
  var theTable = document.getElementById(id)
  var oo = generateArray(theTable)
  var ranges = oo[1]
 
  /* original data */
  var data = oo[0]
  var ws_name = "SheetJS"
 
  var wb = new Workbook(),
    ws = sheet_from_array_of_arrays(data)
 
  /* add ranges to worksheet */
  // ws['!cols'] = ['apple', 'banan'];
  ws["!merges"] = ranges
 
  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name)
  wb.Sheets[ws_name] = ws
 
  var wbout = XLSX.write(wb, {
    bookType: "xlsx",
    bookSST: false,
    type: "binary"
  })
 
  saveAs(
    new Blob([s2ab(wbout)], {
      type: "application/octet-stream"
    }),
    "test.xlsx"
  )
}
 
 
 
//主要修改此函数内的方法
 
export function export_json_to_excel({
  multiHeader = [],
  header,
  data,
  sheetname,
  filename,
  merges = [],
  autoWidth = true,
  bookType = "xlsx"
} = {}) {
  /* original data */
  filename = filename || "excel-list"
  data = [...data]
 
  for (var i = 0; i < header.length; i++) {
    data[i].unshift(header[i])
  }
 
  // data.unshift(header)
 
  for (let i = multiHeader.length - 1; i > -1; i--) {
    data.unshift(multiHeader[i])
  }
 
  var ws_name = sheetname
  var wb = new Workbook(),
    ws = []
  for (var j = 0; j < header.length; j++) {
    ws.push(sheet_from_array_of_arrays(data[j]))
  }
 
  if (merges.length > 0) {
    if (!ws["!merges"]) ws["!merges"] = []
    merges.forEach(item => {
      ws["!merges"].push(XLSX.utils.decode_range(item))
    })
  }
  // console.log("width", autoWidth)
  if (autoWidth) {
    /*设置worksheet每列的最大宽度*/
    var colWidth = []
    for (var k = 0; k < header.length; k++) {
      colWidth.push(
        data[k].map(row =>
          row.map(val => {
            /*先判断是否为null/undefined*/
            if (val == null) {
              return {
                wch: 10
              }
            } else if (val.toString().charCodeAt(0) > 255) {
              /*再判断是否为中文*/
              return {
                wch: val.toString().length * 2
              }
            } else {
              return {
                wch: val.toString().length
              }
            }
          })
        )
      )
    }
 
    /*以第一行为初始值*/
    let result = []
    for (var k = 0; k < colWidth.length; k++) {
      result[k] = colWidth[k][0]
      for (let i = 1; i < colWidth[k].length; i++) {
        for (let j = 0; j < colWidth[k][i].length; j++) {
          if (result[k][j]["wch"] < colWidth[k][i][j]["wch"]) {
            result[k][j]["wch"] = colWidth[k][i][j]["wch"]
          }
        }
      }
    }
    // 分别给sheet表设置宽度
    for (var l = 0; l < result.length; l++) {
      ws[l]["!cols"] = result[l]
    }
  }
 
  /* add worksheet to workbook */
  for (var k = 0; k < header.length; k++) {
    wb.SheetNames.push(ws_name[k])
    wb.Sheets[ws_name[k]] = ws[k]
  }
 
  var wbout = XLSX.write(wb, {
    bookType: bookType,
    bookSST: false,
    type: "binary"
  })
  saveAs(
    new Blob([s2ab(wbout)], {
      type: "application/octet-stream"
    }),
    `${filename}.${bookType}`
  )
}

3、在src中新建utils 新建文件setMethods.js

utils/setMethods.js

 
 
/**
 * Parse the time to string
 * @param {(Object|string|number)} time
 * @param {string} cFormat
 * @returns {string}
 */
export function parseTime (time, cFormat) {
    if (arguments.length === 0) {
      return null
    }
    const format = cFormat || "{y}-{m}-{d} {h}:{i}:{s}"
    let date
    if (typeof time === "object") {
      date = time
    } else {
      if (typeof time === "string" && /^[0-9]+$/.test(time)) {
        time = parseInt(time)
      }
      if (typeof time === "number" && time.toString().length === 10) {
        time = time * 1000
      }
      date = new Date(time)
    }
    const formatObj = {
      y: date.getFullYear(),
      m: date.getMonth() + 1,
      d: date.getDate(),
      h: date.getHours(),
      i: date.getMinutes(),
      s: date.getSeconds(),
      a: date.getDay()
    }
    // eslint-disable-next-line
    const time_str = format.replace(/{(y|m|d|h|i|s|a)+}/g, (result, key) => {
      let value = formatObj[key]
      // Note: getDay() returns 0 on Sunday
      if (key === "a") {
        return ["日", "一", "二", "三", "四", "五", "六"][value]
      }
      if (result.length > 0 && value < 10) {
        value = "0" + value
      }
      return value || 0
    })
    // eslint-disable-next-line
    return time_str
  }
   
  /**
   * Parse the json to excel
   *  tableJson 导出数据 ; filenames导出表的名字; autowidth表格宽度自动 true or false; bookTypes xlsx & csv & txt
   * @param {(Object)} tableJson
   * @param {string} filenames
   * @param {boolean} autowidth
   * @param {string} bookTypes
   */
  export function json2excel (tableJson, filenames, autowidth, bookTypes) {
    import("./Export2Excel").then(excel => {
      var tHeader = []
      var dataArr = []
      var sheetnames = []
      for (var i in tableJson) {
        tHeader.push(tableJson[i].tHeader)
        dataArr.push(formatJson(tableJson[i].filterVal, tableJson[i].tableDatas))
        sheetnames.push(tableJson[i].sheetName)
      }
      excel.export_json_to_excel({
        header: tHeader,
        data: dataArr,
        sheetname: sheetnames,
        filename: filenames,
        autoWidth: autowidth,
        bookType: bookTypes
      })
    })
  }
  // 数据过滤，时间过滤
  function formatJson (filterVal, jsonData) {
    return jsonData.map(v =>
      filterVal.map(j => {
        if (j === "timestamp") {
          return parseTime(v[j])
        } else {
          return v[j]
        }
      })
    )
  }

4、在 .vue文件组件中调用封装的函数

import { json2excel } from '@/utils/setMethods.js'
 // 下载excel
  async downloadExcel(taskId: string, taskName: string, status: number, index: number) {
  
    var excelDatas = [
      {
        tHeader: ['Id', 'Title', 'Author', 'Readings', 'Date'], // sheet表一头部
        filterVal: ['id', 'title', 'author', 'pageviews', 'display_time'], // 表一的数据字段
        tableDatas: this.list, // 表一的整体json数据
        sheetName: 'sheet1' // 表一的sheet名字
      },
      {
        tHeader: ['序号', '标题', '作者', '服务'],
        filterVal: ['id', 'title', 'author', 'reviewer'],
        tableDatas: this.list,
        sheetName: 'sheet2'
      },
      {
        tHeader: ['序号', '名字', '描述'],
        filterVal: ['userId', 'userName', 'userDescription'],
        tableDatas: this.list,
        sheetName: 'sheet5555'
      }
    ]
    //   引入的函数
    json2excel(excelDatas, '数据报表', true, 'xlsx')
  }