vue前端导出多级表头的excel表的示例代码

npm install xlsx file-saver -s

npm install xlsx

/* 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}`);
}

import { export_json_to_excel } from "@/assets/js/export2excel";

data() {
    return {
        transforlist: [], //表格数据源
        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'
      });
    }
}