VUE+ElementUI导出复杂（多级表头、合并单元格）excel表格

一个超简单实用的excel导出，之前看网上很多教程都是修改配置文件来操作的，这种方法是直接通过数据导出，
所以会觉得麻烦，其实只需要把要导出的表格用el-table渲染出来，然后导出就可以了。当然这种只是针对于数
据不多，如果数据太多都上万条了，这种还是让后端来搞。

1.安装

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

2.在src目录下建excle文件夹下创建两个文件（两个文件代码放在文章最后）。

3.main.js下引入两个文件

import Blob from './excel/Blob.js'
import Export2Excel from './excel/Export2Excel.js'

4.在页面上引入需要的组件

import { saveAs } from "file-saver";
import XLSX from "xlsx";

5.使用

<template>
<div>
  <el-table
    ref="report-table"
    :data="tableData"
    style="width: 100%">
    <el-table-column
      prop="date"
      label="日期"
      width="150">
    </el-table-column>
    <el-table-column label="配送信息">
      <el-table-column
        prop="name"
        label="姓名"
        width="120">
      </el-table-column>
      <el-table-column label="地址">
        <el-table-column
          prop="province"
          label="省份"
          width="120">
        </el-table-column>
        <el-table-column
          prop="city"
          label="市区"
          width="120">
        </el-table-column>
        <el-table-column
          prop="address"
          label="地址"
          width="300">
        </el-table-column>
        <el-table-column
          prop="zip"
          label="邮编"
          width="120">
        </el-table-column>
      </el-table-column>
    </el-table-column>
  </el-table>
  <el-button @click="exportExcel(123)">导出</el-button>
  </div>
</template>

<script>
import FileSaver from 'file-saver'
import XLSX from 'xlsx'
export default {
  name: 'project',
  data() {
      return {
        tableData: [{
          date: '2016-05-03',
          name: '王小虎',
          province: '上海',
          city: '普陀区',
          address: '上海市普陀区金沙江路 1518 弄',
          zip: 200333
        }, {
          date: '2016-05-02',
          name: '王小虎',
          province: '上海',
          city: '普陀区',
          address: '上海市普陀区金沙江路 1518 弄',
          zip: 200333
        }, {
          date: '2016-05-04',
          name: '王小虎',
          province: '上海',
          city: '普陀区',
          address: '上海市普陀区金沙江路 1518 弄',
          zip: 200333
        }, {
          date: '2016-05-01',
          name: '王小虎',
          province: '上海',
          city: '普陀区',
          address: '上海市普陀区金沙江路 1518 弄',
          zip: 200333
        }, {
          date: '2016-05-08',
          name: '王小虎',
          province: '上海',
          city: '普陀区',
          address: '上海市普陀区金沙江路 1518 弄',
          zip: 200333
        }, {
          date: '2016-05-06',
          name: '王小虎',
          province: '上海',
          city: '普陀区',
          address: '上海市普陀区金沙江路 1518 弄',
          zip: 200333
        }, {
          date: '2016-05-07',
          name: '王小虎',
          province: '上海',
          city: '普陀区',
          address: '上海市普陀区金沙江路 1518 弄',
          zip: 200333
        }]
      }
    },
  components: {

  },
  watch: {

  },
  methods: {
    exportExcel(excelName) {
      try {
        const $e = this.$refs['report-table'].$el
        let $table = $e.querySelector('.el-table__fixed')
        if(!$table) {
          $table = $e
        }

        const wb = XLSX.utils.table_to_book($table, {raw:true})
        const wbout = XLSX.write(wb, {bookType: 'xlsx', bookSST:true, type: 'array'})
        FileSaver.saveAs(
          new Blob([wbout],{type: 'application/octet-stream'}),
          `${excelName}.xlsx`,
        )
      } catch (e) {
        if (typeof console !== 'undefined') console.error(e)
      }
    }
  },
  mounted () {
  }
}
</script>
<style>

</style>

到这里就可以，打完收工！
Blob.js

/* eslint-disable */
/* Blob.js*/
 
/*global self, unescape */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
  plusplus: true */
 
/*! @source http://purl.eligrey.com/github/Blob.js/blob/master/Blob.js */
 
(function (view) {
    "use strict";
 
    view.URL = view.URL || view.webkitURL;
 
    if (view.Blob && view.URL) {
        try {
            new Blob;
            return;
        } catch (e) {
        }
    }
 
    // Internally we use a BlobBuilder implementation to base Blob off of
    // in order to support older browsers that only have BlobBuilder
    var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || (function (view) {
        var
            get_class = function (object) {
                return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
            }
            , FakeBlobBuilder = function BlobBuilder() {
                this.data = [];
            }
            , FakeBlob = function Blob(data, type, encoding) {
                this.data = data;
                this.size = data.length;
                this.type = type;
                this.encoding = encoding;
            }
            , FBB_proto = FakeBlobBuilder.prototype
            , FB_proto = FakeBlob.prototype
            , FileReaderSync = view.FileReaderSync
            , FileException = function (type) {
                this.code = this[this.name = type];
            }
            , file_ex_codes = (
                "NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR "
                + "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
            ).split(" ")
            , file_ex_code = file_ex_codes.length
            , real_URL = view.URL || view.webkitURL || view
            , real_create_object_URL = real_URL.createObjectURL
            , real_revoke_object_URL = real_URL.revokeObjectURL
            , URL = real_URL
            , btoa = view.btoa
            , atob = view.atob
 
            , ArrayBuffer = view.ArrayBuffer
            , Uint8Array = view.Uint8Array
 
            , origin = /^[\w-]+:\/*\[?[\w\.:-]+\]?(?::[0-9]+)?/
        ;
        FakeBlob.fake = FB_proto.fake = true;
        while (file_ex_code--) {
            FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
        }
        // Polyfill URL
        if (!real_URL.createObjectURL) {
            URL = view.URL = function (uri) {
                var
                    uri_info = document.createElementNS("http://www.w3.org/1999/xhtml", "a")
                    , uri_origin
                ;
                uri_info.href = uri;
                if (!("origin" in uri_info)) {
                    if (uri_info.protocol.toLowerCase() === "data:") {
                        uri_info.origin = null;
                    } else {
                        uri_origin = uri.match(origin);
                        uri_info.origin = uri_origin && uri_origin[1];
                    }
                }
                return uri_info;
            };
        }
        URL.createObjectURL = function (blob) {
            var
                type = blob.type
                , data_URI_header
            ;
            if (type === null) {
                type = "application/octet-stream";
            }
            if (blob instanceof FakeBlob) {
                data_URI_header = "data:" + type;
                if (blob.encoding === "base64") {
                    return data_URI_header + ";base64," + blob.data;
                } else if (blob.encoding === "URI") {
                    return data_URI_header + "," + decodeURIComponent(blob.data);
                }
                if (btoa) {
                    return data_URI_header + ";base64," + btoa(blob.data);
                } else {
                    return data_URI_header + "," + encodeURIComponent(blob.data);
                }
            } else if (real_create_object_URL) {
                return real_create_object_URL.call(real_URL, blob);
            }
        };
        URL.revokeObjectURL = function (object_URL) {
            if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) {
                real_revoke_object_URL.call(real_URL, object_URL);
            }
        };
        FBB_proto.append = function (data/*, endings*/) {
            var bb = this.data;
            // decode data to a binary string
            if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
                var
                    str = ""
                    , buf = new Uint8Array(data)
                    , i = 0
                    , buf_len = buf.length
                ;
                for (; i < buf_len; i++) {
                    str += String.fromCharCode(buf[i]);
                }
                bb.push(str);
            } else if (get_class(data) === "Blob" || get_class(data) === "File") {
                if (FileReaderSync) {
                    var fr = new FileReaderSync;
                    bb.push(fr.readAsBinaryString(data));
                } else {
                    // async FileReader won't work as BlobBuilder is sync
                    throw new FileException("NOT_READABLE_ERR");
                }
            } else if (data instanceof FakeBlob) {
                if (data.encoding === "base64" && atob) {
                    bb.push(atob(data.data));
                } else if (data.encoding === "URI") {
                    bb.push(decodeURIComponent(data.data));
                } else if (data.encoding === "raw") {
                    bb.push(data.data);
                }
            } else {
                if (typeof data !== "string") {
                    data += ""; // convert unsupported types to strings
                }
                // decode UTF-16 to binary string
                bb.push(unescape(encodeURIComponent(data)));
            }
        };
        FBB_proto.getBlob = function (type) {
            if (!arguments.length) {
                type = null;
            }
            return new FakeBlob(this.data.join(""), type, "raw");
        };
        FBB_proto.toString = function () {
            return "[object BlobBuilder]";
        };
        FB_proto.slice = function (start, end, type) {
            var args = arguments.length;
            if (args < 3) {
                type = null;
            }
            return new FakeBlob(
                this.data.slice(start, args > 1 ? end : this.data.length)
                , type
                , this.encoding
            );
        };
        FB_proto.toString = function () {
            return "[object Blob]";
        };
        FB_proto.close = function () {
            this.size = 0;
            delete this.data;
        };
        return FakeBlobBuilder;
    }(view));
 
    view.Blob = function (blobParts, options) {
        var type = options ? (options.type || "") : "";
        var builder = new BlobBuilder();
        if (blobParts) {
            for (var i = 0, len = blobParts.length; i < len; i++) {
                if (Uint8Array && blobParts[i] instanceof Uint8Array) {
                    builder.append(blobParts[i].buffer);
                }
                else {
                    builder.append(blobParts[i]);
                }
            }
        }
        var blob = builder.getBlob(type);
        if (!blob.slice && blob.webkitSlice) {
            blob.slice = blob.webkitSlice;
        }
        return blob;
    };
 
    var getPrototypeOf = Object.getPrototypeOf || function (object) {
        return object.__proto__;
    };
    view.Blob.prototype = getPrototypeOf(new view.Blob());
}(
    typeof self !== "undefined" && self
    || typeof window !== "undefined" && window
    || this
));

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")
}
// 使用复杂表头的关键是，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}`);
}