导入excel文件组件封装

很多项目中都有批量导入数据功能，本次引入第三方excel库xlsx.js的api解析文件成为我们方便处理的对象

1. 安装xlsx.js

npm install xlsx

2. 导入excel组件封装

<template>
  <div>
    <input id="excel-upload-input" ref="excel-upload-input" type="file" accept=".xlsx, .xls" class="c-hide" @change="handkeFileChange">
    <div id="drop" @drop="handleDrop" @dragover="handleDragover" @dragenter="handleDragover">

          拖拽excel文件到这或
          <el-button style="margin-left:16px;" size="mini" type="primary" @click="handleUpload">打开</el-button>
           <el-button type="text"  style="font-size: 10px;" @click="handleUpload" >批量导入前，请仔细核对信息</el-button>

    </div>
  </div>
</template>

<script>
import XLSX from 'xlsx'

export default {
  data() {
    return {
      loading: false,
      excelData: {
        header: null,
        results: null
      }
    }
  },
  methods: {
    generateDate({ header, results }) {
    	// 处理空列
        for (let i = 0; i < header.length; i++) {
            if (header[i].toLocaleLowerCase().indexOf('unknown') === 0) {
                header.splice(i, 1)
                i--
            }
        }
      this.excelData.header = header
      this.excelData.results = results
      this.$emit('on-selected-file', this.excelData)
    },
    handleDrop(e) {
      e.stopPropagation()
      e.preventDefault()
      const files = e.dataTransfer.files
      if (files.length !== 1) {
        this.$message.error('仅支持一个文件上传!')
        return
      }
      const itemFile = files[0] // only use files[0]
      this.readerData(itemFile)
      e.stopPropagation()
      e.preventDefault()
    },
    handleDragover(e) {
      e.stopPropagation()
      e.preventDefault()
      e.dataTransfer.dropEffect = 'copy'
    },
    handleUpload() {
      document.getElementById('excel-upload-input').click()
    },
    handkeFileChange(e) {
      const files = e.target.files
      const itemFile = files[0] // only use files[0]
      if (!itemFile) return
      this.readerData(itemFile)
      this.$refs['excel-upload-input'].value = null // fix can't select the same excel
    },
    readerData(itemFile) {
      const reader = new FileReader()
      reader.onload = e => {
        const data = e.target.result
        const fixedData = this.fixdata(data)
        const workbook = XLSX.read(btoa(fixedData), { type: 'base64' })
        const firstSheetName = workbook.SheetNames[0]
        const worksheet = workbook.Sheets[firstSheetName]
        const header = this.get_header_row(worksheet)
        const results = XLSX.utils.sheet_to_json(worksheet)
        this.generateDate({ header, results })
      }
      reader.readAsArrayBuffer(itemFile)
    },
    fixdata(data) {
      var o = ''
      var l = 0
      const w = 10240
      for (; l < data.byteLength / w; ++l) o += String.fromCharCode.apply(null, new Uint8Array(data.slice(l * w, l * w + w)))
      o += String.fromCharCode.apply(null, new Uint8Array(data.slice(l * w)))
      return o
    },
    get_header_row(sheet) {
      const headers = []
      const range = XLSX.utils.decode_range(sheet['!ref'])
      var C
      const R = range.s.r /* start in the first row */
      for (C = range.s.c; C <= range.e.c; ++C) { /* walk every column in the range */
        var cell = sheet[XLSX.utils.encode_cell({ c: C, r: R })] /* find the cell in the first row */
        var hdr = 'UNKNOWN ' + C // <-- replace with your desired default
        if (cell && cell.t) hdr = XLSX.utils.format_cell(cell)
        headers.push(hdr)
      }
      return headers
    }
  }
}
</script>
 <style scoped>
 #excel-upload-input{
  display: none;
  z-index: -99999;
 }
 #drop {
  border: 2px dashed #bbb;
  width: 600px;
  height: 160px;
  line-height: 160px;
  margin: 0 auto;
  font-size: 24px;
  border-radius: 5px;
  text-align: center;
  color: #bbb;
  position: relative;
 }
 </style>

3. 引入组件使用

<template>
    <div>
        <upload-excel-component @on-selected-file="selected"></upload-excel-component>
    </div>
</template>

<script>
import UploadExcelComponent from '@/components/UploadExcel/index.vue'
export default {
    components: {
        UploadExcelComponent,
    },
    data() {
        return {

        }
    },
    methods: {
        selected(data) {
            console.log(data.header) // ['学生','性别','年龄']
            console.log(data.results) // [{'学生': '张三','性别': '男','年龄': '18'},{'学生': '李四','性别': '男','年龄': '20'}]
        }
    }
}
</script>