Vue 使用Export2Excel 导出 excel文件

小知识，大挑战！本文正在参与“程序员必备小知识”创作活动。

A journey of a thousand miles begins with single step

背景

在我们公司项目中使用最多的就是根据条件查出数据，然后使用表格（el-table）进行数据展示，既然用表格展示了数据，就不可避免的要对数据进行导出操作。 虽然一般在公司中，导出数据都是后端进行处理，返回前端一个地址进行下载，但是由于我们公司后端人员工时费比较高，这项工作就由前端进行完成了，经过上网搜索，发现使用 Export2Excel 导出特别挺简单的，就开始使用了，现在这已经是我们项目中使用最多的功能。

安装

-S === --save -D === --save-dev

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

# use yarn
yarn add file-saver xlsx
yarn add file-saver script-loader --dev

引入 Export2Excel 文件

在网上下载在Export2Excel.js文件，放在自己项目中合适的位置。

代码地址：gitee.com/yunxii/vue-…

代码如下：

/* eslint-disable */
require('script-loader!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,
  excelWidth = 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
          }
        } 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 = 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
  }

  if (excelWidth) {
    /*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
          }
        } else if (val.toString().charCodeAt(0) > 255) {
        /*再判断是否为中文*/
          return {
            wch: 20
          }
        } else if (val.toString().indexOf("<operation") !== -1) {
          /* 判断是否为报文数据*/
          return {
            wch: 30
          }
        } 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}`
  )
}

使用

在项目中创建一个 vue 文件， 配置好路由方便测试，项目中使用的是elementUI组件库

在模板中

<el-button type="primary" icon="el-icon-download" @click="onExcelDown">导出</el-button>

在methods中写导出的方法

async onExcelDown() {
    this.$message({ type: 'warning', message: '数据读取中，请稍后' })
    this.loading = true
    // 此处获取后端接口数据
    await this.getExportData()
    this.loading = false
    const filename = '报表数据'
    const autoWidth = true
    const bookType = 'xlsx'
    const header = [ '时间点要求', '报告名称', '需求室', '维护', 'BOSS']
    const headValue = [ 'ask', 'reportName', 'xqs', 'whs', 'boss'']
    const formatJson = (headValue, jsonData) => {
      return jsonData.map((v) => headValue.map((j) => v[j]))
    }
    this.$confirm('确定导出内容', '提示', {
        cancelButtonClass: 'btn-custom-cancel',
        confirmButtonText: '确定',
        cancelButtonText: '取消',
        type: 'warning'
    }).then(() => {
        // 引入本地的 Export2Excel.js
        import('@/vendor/Export2Excel.js').then(moudle => {
            moudle.export_json_to_excel({
                header,
                // this.exportData 是后端获取的数据
                data: formatJson(headValue, this.exportData),
                filename,
                autoWidth,
                bookType
            })
        })
    }).catch(() => {
        this.$message({ type: 'info', message: '已取消导出' })
    })
},

效果如下

案例代码

Export2Excel 案例使用代码：

gitee.com/yunxii/vue-…