vue 导出excel，合并单元格，修改样式

1. 安装

npm i file-saver
npm i xlsx
npm i xlsx-style

如果运行中报错

在\node_modules\xlsx-style\dist\cpexcel.js 807行把 var cpt = require('./cpt' + 'able'); 
改成 var cpt = cptable;

2. 创建@/utils/Blob.js文件

/* eslint-disable */
/* Blob.js
 * A Blob implementation.
 * 2014-05-27
 *
 * By Eli Grey, http://eligrey.com
 * By Devin Samarin, https://github.com/eboyjr
 * License: X11/MIT
 *   See LICENSE.md
 */
 
/*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
                ;
            FakeBlob.fake = FB_proto.fake = true;
            while (file_ex_code--) {
                FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
            }
            if (!real_URL.createObjectURL) {
                URL = view.URL = {};
            }
            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 = this.data.length = 0;
            };
            return FakeBlobBuilder;
        }(view));
 
    view.Blob = function Blob(blobParts, options) {
        var type = options ? (options.type || "") : "";
        var builder = new BlobBuilder();
        if (blobParts) {
            for (var i = 0, len = blobParts.length; i < len; i++) {
                builder.append(blobParts[i]);
            }
        }
        return builder.getBlob(type);
    };
}(typeof self !== "undefined" && self || typeof window !== "undefined" && window || this.content || this));

3. 创建@/utils/Export2Excel.js文件

require('script-loader!file-saver');
require('./Blob.js'); 
require('script-loader!xlsx/dist/xlsx.core.min');
import * as XLSX from 'xlsx';
import XLSXS from 'xlsx-style';
import { saveAs } from 'file-saver';
function sheet_from_array_of_arrays(data) {
  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;
}

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);
}
export function export_json_to_excelhb({
  multiHeader2 = [], // 第一行表头
  multiHeader = [], // 第二行表头
  header, // 第三行表头
  data, //传递的数据
  filename, //文件名
  merges = [], // 合并
  autoWidth = true, //用于设置列宽的
  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);
  // let borderAll = {
  //   //单元格外侧框线
  //   top: {
  //     style: 'medium'
  //   },
  //   bottom: {
  //     style: 'medium'
  //   },
  //   left: {
  //     style: 'medium'
  //   },
  //   right: {
  //     style: 'medium'
  //   }
  // };

  for (let key in ws) {
    if (ws[key] instanceof Object) {
      ws[key].s = {
        // border: borderAll,
        alignment: {
          horizontal: 'center', //水平居中对齐
          vertical: 'center', //垂直居中
          wrapText: 1 //自动换行
        },
        font: {
          sz: 12 //单元格中字体的样式与颜色设置
          // color: {
          //   rgb: '495060'
          // }
        },
        bold: true,
        numFmt: 0
      };
    }
  }
  ws['I2'] = ws['H2'] = ws['G2'] = ws['F2'] = ws['E2'] = ws['D2'] = ws['C2'] = ws['B2'] = ws['A2']; //用于第二行的单元格的样式设置（如果是合并的第一行，就是1）
  if (merges.length > 0) {
    if (!ws['!merges']) ws['!merges'] = [];
    merges.forEach(item => {
      ws['!merges'].push(XLSX.utils.decode_range(item));
    });
  }
  if (autoWidth) {
    let colWidths = [];
    // 计算每一列的所有单元格宽度
    // 先遍历行
    data.forEach(row => {
      // 列序号
      let index = 0;
      // 遍历列
      for (const key in row) {
        if (colWidths[index] == null) colWidths[index] = [];
        switch (typeof row[key]) {
          case 'string':
          case 'number':
          case 'boolean':
            colWidths[index].push(getCellWidth(row[key]));
            break;
          case 'object':
          case 'function':
            colWidths[index].push(0);
            break;
        }
        index++;
      }
    });
    ws['!cols'] = [];
    colWidths.forEach((widths, index) => {
      // 计算列头的宽度
      widths.push(getCellWidth(header[index]));
      // 设置最大值为列宽
      ws['!cols'].push({
        wch: Math.max(...widths)
      });
    });
  }
  console.log(ws);
  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name);
  wb.Sheets[ws_name] = ws;
  var wbout = XLSXS.write(wb, {
    bookType: bookType,
    bookSST: false,
    type: 'binary'
  });
  saveAs(
    new Blob([s2ab(wbout)], {
      type: 'application/octet-stream'
    }),
    `${filename}.${bookType}`
  );
}
export function getCellWidth(value) {
  if (value == null) {
    return 12;
  } else if (value.toString().charCodeAt(0) > 255) {
    // 判断是否包含中文
    let length = value.toString().length * 2;
    if (length > 60) {
      length = length - 40;
      //这里的宽度可以自己设定，在前面设置wrapText: 1可以在单元格内换行
    }
    return length;
  } else {
    return value.toString().length * 1.2;
  }
}

4. 在vue文件中的methods方法中写一个方法

 confirmExport () {
      import('@/utils/Export2Excel').then(excel => {
        const header = [
          '问题ID',
          '问题标题',
          '提问时间'
        ]; // 表头
        const filterVal = [
          'id',
          'title',
          'intime',
        ]; // 表头所对应的字段，这里未填写，请自行填写对应的字段，按实际需求请自行处理该步
        let rjdata = [];
        this.multipleSelection.map(ele => {
          rjdata.push(ele.q_id);
        });
        // 调一下接口，获取数据， rjdata 参数
        doExportHejian({ ids: rjdata }).then(res => {
        // =================================================================================================
          // 进行所有表头的单元格合并
          const merges = []; //需要合并的单元格
          let allList = [];
          const letter = [
            'A',
            'B',
            'C'
          ];
          const list = res.data;
          let point = 1;
          // 需要合并的单元格的js  ================
          for (let j = 0; j < list.length; j++) {
            if (list[j].implementTargetEntities !== null) {
              for (let i = 0; i < letter.length; i++) {
                let str = letter[i] + (point + 1) + ':' + letter[i] + (point + list[j].implementTargetEntities.length);
                merges.push(str);
              }
              point += list[j].implementTargetEntities.length;
            }
          }
          // 需要合并的单元格的js  ================
          list.map(ele => {
            if (ele.implementTargetEntities !== null) {
              for (let i = 0; i < ele.implementTargetEntities.length; i++) {
                allList.push({ ...ele, ...ele.implementTargetEntities[i] });
                delete allList[allList.length - 1].implementTargetEntities;
              }
            } else {
              allList.push({ ...ele });
              delete allList[allList.length - 1].implementTargetEntities;
            }
          });
          allList.map(item => {
            for (let key in item) {
              const el = document.createElement('div');
              el.innerHTML = item[key];
              item[key] = el.textContent;
            }
          });
         // =============================================================================  处理我的数据，算一下我哪些需要合并
          let excelname = 'xxxx'; //导出的excel的名字
          let data = allList.map(v => filterVal.map(j => v[j])); 
          excel.export_json_to_excelhb({
            // multiHeader, // 这里是第一行的表头
            // multiHeader2, // 这里是第二行的表头
            header: header, // 这里是第三行的表头
            data,
            filename: excelname,
            merges
          });
        });
      });
    }