vue element admin 导出带有sheet的excel

lender提了个需求，要求实现导出excel并且要分sheet页，博主非常依赖框架，以为框架的代码示例里会有，结果找了一圈都没看见，非常蛋疼只能自己改写代码了

改写函数部分

在框架根目录找到 src/vendor/Export2Excel.js 文件，搜索export_json_to_excel 函数，将代码更改为如下

export function export_json_to_excel({
  multiHeader = [],
  header,
  data,
  filename,
  merges = [],
  autoWidth = true,
  bookType = 'xlsx',
  sheet = [] // 增加sheet参数
} = {}) {
  /* original data */
  filename = filename || 'excel-list'
  var wb = new Workbook()

  // 判断是否传入sheet参数
  if (sheet.length === 0) {
    sheet = ["sheet1"] // 处理默认sheet名
    var data1 = [...data]
    data1.unshift(header)
    for (let i = multiHeader.length - 1; i > -1; i--) {
      data1.unshift(multiHeader[i])
    }
    data = [[...data1]]
  } else {
    var datas = []
    data.forEach((row, index) => {
      row.unshift(header[index])
      if (multiHeader.length) {
        for (let i = multiHeader[index].length - 1; i > -1; i--) {
          row.unshift(multiHeader[index][i])
        }
      }
      datas.push(row)
    })
    data = [...datas]
  }

  sheet.forEach((ws_name, index) => {
    var ws = sheet_from_array_of_arrays(data[index])
    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[index].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;
  })

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

示例使用部分

这里拿学校学生表做为演示示例

<template>
  <el-link type="primary" :underline="false" icon="el-icon-download" @click="exportTable">导出表</el-link>
</template>
<script>
export default {
  methods: {
    exportTable() {
      import('@/vendor/Export2Excel').then(excel => {
        // 设置header
        var header1 = ['姓名', '性别', '年龄', '班级']
        var header2 = ['班级', '学生数']
        // 设置data
        var data1 = [['小明', '男', '12', '1'], ['小红', '女', '12', '1'], ['小刚', '男', '12', '2']]
        var data2 = [['1班', '2人'], ['2班', '1人']]
        excel.export_json_to_excel({
          header: [header1, header2],
          data: [data1, data2],
          filename: '校园5年级学生表',
          autoWidth: true,
          bookType: 'xlsx',
          sheet: ['学生5年级表', '班级5年级表'] // 设置sheet页名称
        })
      })
    }
  }
}
</script>