vue前端导出多级表头的excel表

1.安装npm依赖

npm install xlsx file-saver -S

npm install xlsx

2.引入完整的Export2Excel.js：

/* 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")
}
// 对此方法进行修改，如下：
export function export_json_to_excel({
    multiHeader2 = [],	// 第一行表头
    multiHeader = [], // 第二行表头
    header,	// 第三行表头
    data,
    filename, //文件名
    merges = [], // 合并
    autoWidth = true,
    bookType = 'xlsx'
} = {}) {
    /* original data */
    filename = filename || '列表';
    data = [...data]
    data.unshift(header);

    for (let i = multiHeader2.length - 1; i > -1; i--) {
        data.unshift(multiHeader2[i])
    }

    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;

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

3.vue文件中引入：

import { export_json_to_excel } from "@/assets/js/Export2Excel";

4.直接上js,其他的布局之类的我就不展示了

data() {
    return {
        excelData: [], //表格数据,这个是你自己请求的真实数据
    }
}
methods: {
     //重置EXcel数据
    resetExcelData() {
      this.excelData = [];
      if (this.transforList.length > 0) {
        for (let excelItem of this.transforList) {
          // console.log(excelItem.transformerEntityList);
          let excelObj = {
            plantname:
              excelItem.plantname != null && excelItem.plantname != undefined
                ? excelItem.plantname
                : "",
            transName:
              excelItem.transName != null && excelItem.transName != undefined
                ? excelItem.transName
                : "",
            ea:
              excelItem.ea != null && excelItem.ea != undefined
                ? excelItem.ea
                : "",
            sa:
              excelItem.sa != null && excelItem.sa != undefined
                ? excelItem.sa
                : "", //视在功率
            pa:
              excelItem.pa != null && excelItem.pa != undefined
                ? excelItem.pa
                : "", //有功功率
            fa:
              excelItem.fa != null && excelItem.fa != undefined
                ? excelItem.fa
                : "", //无功功率
            f:
              excelItem.f != null && excelItem.f != undefined
                ? excelItem.f
                : "", //功率因数
            az:
              excelItem.az != null && excelItem.az != undefined
                ? excelItem.az
                : "", //A相绕组温度
            bz:
              excelItem.bz != null && excelItem.bz != undefined
                ? excelItem.bz
                : "", //B相绕组温度
            cz:
              excelItem.cz != null && excelItem.cz != undefined
                ? excelItem.cz
                : "", //C相绕组温度
            status:
              excelItem.status != null && excelItem.status != undefined
                ? excelItem.status
                : "",
            fuhe: "--%",
          };
          this.excelData.push(excelObj);
        }
      }
    },   

    //json格式化
    formatJson(filterVal, jsonData) {
      jsonData.map((v) => filterVal.map((j) => v[j]));
      return jsonData.map((v) => filterVal.map((j) => v[j]));
    },

    //导出方法
    exportExcel() {
      this.resetExcelData(); 
      const multiHeader = [
        [
          "站点名称",
          "变压器名称",
          "状态",
          "额定容量(kVA)",
          "视在功率(kW)",
          "负荷率(100%)",
          "有功功率(kW)",
          "无功功率(kVar)",
          "功率因数",
          "三相绕组温度",
          "",
          "",
        ]
      ]; //一级表头
      const tHeader = ["", "", "", "", "", "", "", "", "", "A", "B", "C"]; //二级表头
      const filterVal = ["plantname","transName","status","ea","sa","fuhe","pa", "fa","f","az","bz","cz"];//表头所对应后台返回的字段
      // const data = this.excelData.map(v => filterVal.map(j => v[j]));//这一行和下面得六行代码是一样得作用的
      let list = [];
      if (this.excelData == 0) {
        list = this.excelData;
      } else {
        list = this.excelData;
      }
      const data = this.formatJson(filterVal, list);//格式化
      console.log(data);
      //这个得说明一下：网上得博客每个不一样，你那我的直接用也是没啥用得，你的理解这个合并是怎么写的：根据你的多级表头，如果没有合并得从上往下写，遇到开始合并单元格的，从左往右得单行写，从上到下，直到写完整
      const merges = [
        "A1:A2",
        "B1:B2",
        "C1:C2",
        "D1:D2",
        "E1:E2",
        "F1:F2",
        "G1:G2",
        "H1:H2",
        "I1:I2",
        "J1:L1"
      ];
      export_json_to_excel({
        multiHeader, //这里是第一行的表头
        header: tHeader, //这里应该是算第二行的表头
        data,//数据
        merges,//合并行
        filename: "变压器状态" + "_" + new Date().getTime(),
        autoWidth: true,
        bookType: 'xlsx'
      });
    }
}

5.效果：

总结：

我的这个是两级表头，那么三级表头你应该也会做的，只是merges得细心找一下！