Vue用Export2Excel导出excel,多级表头数据

VUE 使用Export2Excel导出数据，以及多级表头

最近公司做项目，需要导出数据到excel表格
使用到了 element UI ，Export2Excel
特此记录，毕竟好记性不如烂笔头
不包含修改样式（菜鸟一枚，希望大佬指教点名）

1.安装依赖 ，三个依赖包

npm install -S file-saver
npm install -S xlsx
npm install -D script-loader

2.创建文件

在项目src 下创建 vendor 文件夹
然后创建 Export2Excel.js 文件

Export2Excel.js 文件内容

/* eslint-disable */
import { saveAs } from 'file-saver'
import XLSX from 'xlsx'

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")
}

export function export_json_to_excel({
  multiHeader = [],
  header,
  data,
  filename,
  merges = [],
  autoWidth = true,
  bookType = 'xlsx',
} = {}) {
  /* original data */
  filename = filename || 'excel-list'
  data = [...data]
  data.unshift(header);

  for (let i = multiHeader.length - 1; i > -1; i--) {
    data.unshift(multiHeader[i])
  }

  var ws_name = "SheetJS";
  var wb = new Workbook(),
    ws = sheet_from_array_of_arrays(data);

  if (merges.length > 0) {
    if (!ws['!merges']) ws['!merges'] = [];
    merges.forEach(item => {
      ws['!merges'].push(XLSX.utils.decode_range(item))
    })
  }

  if (autoWidth) {
    /*设置worksheet每列的最大宽度*/
    const colWidth = data.map(row => row.map(val => {
      /*先判断是否为null/undefined*/
      if (val == null) {
        return {
          'wch': 10
        };
      }
      /*再判断是否为中文*/
      else if (val.toString().charCodeAt(0) > 255) {
        return {
          'wch': val.toString().length * 2
        };
      } else {
        return {
          'wch': val.toString().length
        };
      }
    }))
    /*以第一行为初始值*/
    let result = colWidth[0];
    for (let i = 1; i < colWidth.length; i++) {
      for (let j = 0; j < colWidth[i].length; j++) {
        if (result[j]['wch'] < colWidth[i][j]['wch']) {
          result[j]['wch'] = colWidth[i][j]['wch'];
        }
      }
    }
    ws['!cols'] = result;
  }

  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name);
  wb.Sheets[ws_name] = ws;

  /**
   * 自定义
   */
  var dataInfo = wb.Sheets[wb.SheetNames[0]];
  let arr = [
    "A1",
    "B1",
    "C1",
    "D1",
    "E1",
    "F1",
    "G1",
    "H1",
    "I1",
    "J1",
    "K1",
    "L1",
    "M1",
    "N1",
    "O1",
    "P1",
    "Q1",
    "R1",
    "S1",
    "T1",
    "U1",
    "V1",
    "W1",
    "X1",
    "Y1",
    "Z1"
  ];

  let style = {
    font: {
      color: { rgb: "000000" },
      bold: true
    },
    alignment: {
      horizontal: "center",
      vertical: "center"
    }
  };
  for (var i = 0; i < header.length; i++) {
    dataInfo[arr[i]].s = style;
  }




  var wbout = XLSX.write(wb, {
    bookType: bookType,
    bookSST: false,
    type: 'binary'
  });
  saveAs(new Blob([s2ab(wbout)], {
    type: "application/octet-stream"
  }), `${filename}.${bookType}`);
}

补充：
所用到的数据格式

tableData: [{
			 date: '2016-05-02',
			  name: '王小虎',
			  address: '上海市普陀区金沙江路 1518 弄'
			}, {
			  date: '2016-05-04',
			  name: '王小虎',
			  address: '上海市普陀区金沙江路 1517 弄'
			}, {
			  date: '2016-05-01',
			  name: '王小虎',
			  address: '上海市普陀区金沙江路 1519 弄'
			}, {
			  date: '2016-05-03',
			  name: '王小虎',
			  address: '上海市普陀区金沙江路 1516 弄'
			}]

3.使用方法（一级表头）

导出单级表头

Html部分：

<el-button @click="handleDownload" class="addButton-class">批量导出</el-button>

js部分：

// 导出数据
handleDownload() {
	import('@/vendor/Export2Excel').then(excel => {
		// 表头数据
		const header = ['日期', '条形码', '所属区域', '所属部门', '商场名称', '兑奖员工']
		// 数据来源中，代替表头的变量
		const filterVal = ['create_time', 'bar_code', 'aname', 'dname', 'warehouse_name', 'sell_name']
		// 数据来源
		const list = this.tableData
		// 拼接数据
		const data = this.formatJson(filterVal, list)
		excel.export_json_to_excel({
			header,
          	data,
          	// 导出表格的文件名字
          	filename:'销售产品清单',
         })
    })
},

// 拼接数据
formatJson(filterVal, jsonData) {
	return jsonData.map(v => filterVal.map(j => {
	  return v[j]
	}))
},

示例效果

3.多级表头

导出多级表头

导出多级表头首先要理解，单元格合并

日期 所占 单元格为 A1:A3
配送信息 所占 单元格为 B1:F1
姓名 所占 单元格为 B2:B3
依次类推

理解这一点，下面代码就好理解了

Html部分：

<el-button @click="handleDownload" class="addButton-class">批量导出</el-button>

// 导出单个表头
handleDownload() {
        import('@/vendor/Export2Excel').then(excel => {
          const multiHeader =
          [
            ['对账清单','', '', '', '', '','', '', '', '', ''],// 业务需求可删除
            ['结算单位:',this.name, '', '', '', '','', '结算日期:', this.brginTime, '至', this.endTime], // 业务需求可删除
            ['日期', '上期结存', '', '本期进货', '', '本期退货','', '本期销售', '', '本期库存', ''],
          ] // 前两行的表头数据，二维数组，不够的用空白补全
          const header = ['', '数量', '金额', '数量', '金额', '数量', '金额', '数量', '金额', '数量', '金额'] // 最后一行的表头数据
          const filterVal= ['goods_brand', 'cq_count', 'cq_total', 'bqrk_count', 'bqrk_total', 'bqck_count','bqck_total','bqxs_count','bqxs_total','bqkc_count','bqkc_total']
          // 这里要注意 header  和 filterVal 的数组长度一定要相等，否则会报错
          const list = this.tableData
          const data = this.formatJson(filterVal, list)
          const merges = ['A1:K1','A3:A4','B3:C3','D3:E3','F3:G3','H3:I3','J3:K3'] // 合并单元格的数据，如何合并参考上面图片讲解
          excel.export_json_to_excel({
            multiHeader,
            header,
            merges,
            data,
            filename:'对账清单',
          })
        })
    },
// 拼接数据
formatJson(filterVal, jsonData) {
	return jsonData.map(v => filterVal.map(j => {
	  return v[j]
	}))
},

大致就是这样，就是没有居中效果（菜鸟，勿喷）