1.安装依赖

尽量先设定好用国内淘宝镜像，不然很可能安装出问题。

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

2.新建文件夹，放置 Blob.js 和 export2Excel.js

放在assets下面。

Blob.js

/*! @source http://purl.eligrey.com/github/Blob.js/blob/master/Blob.js */
(function (view) {
  view.URL = view.URL || view.webkitURL;
  if (view.Blob && view.URL) {
    try {
      new Blob;
      return
    } catch (e) {
    }
  }
  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) {
      var bb = this.data;
      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 {
            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 += ""
            }
            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));

export2Excel.js

/* eslint-disable */
require('script-loader!file-saver');
require('script-loader!./../excel/Blob');
require('script-loader!xlsx/dist/xlsx.core.min');

function generateArray(table) {
  let out = [];
  let rows = table.querySelectorAll('tr');
  let ranges = [];
  for (let R = 0; R < rows.length; ++R) {
    let outRow = [];
    let row = rows[R];
    let columns = row.querySelectorAll('td');
    for (let C = 0; C < columns.length; ++C) {
      let cell = columns[C];
      let colspan = cell.getAttribute('colspan');
      let rowspan = cell.getAttribute('rowspan');
      let 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 (let 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 (let k = 0; k < colspan - 1; ++k) outRow.push(null);
    }
    out.push(outRow);
  }
  return [out, ranges];
};

function datenum(v, date1904) {
  if (date1904) v += 1462;
  let 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) {
  let ws = {};
  let range = {s: {c: 10000000, r: 10000000}, e: {c: 0, r: 0}};
  for (let R = 0; R !== data.length; ++R) {
    for (let 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;
      let cell = {v: data[R][C]};
      if (cell.v == null) continue;
      let 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) {
  let buf = new ArrayBuffer(s.length);
  let view = new Uint8Array(buf);
  for (let i = 0; i !== s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
  return buf;
}

export function export_table_to_excel(id) {
  let theTable = document.getElementById(id);
  let oo = generateArray(theTable);
  let ranges = oo[1];

  /* original data */
  let data = oo[0];
  let ws_name = "SheetJS";
  console.log(data);

  let 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;

  let wbout = XLSX.write(wb, {bookType: 'xlsx', bookSST: false, type: 'binary'});

  saveAs(new Blob([s2ab(wbout)], {type: "application/octet-stream"}), "test.xlsx")
}

function formatJson(jsonData) {
  console.log(jsonData)
}

export function export_json_to_excel(th, jsonData, defaultTitle) {

  /* original data */

  let data = jsonData;
  data.unshift(th);
  let ws_name = "SheetJS";

  let wb = new Workbook(), ws = sheet_from_array_of_arrays(data);


  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name);
  wb.Sheets[ws_name] = ws;

  let wbout = XLSX.write(wb, {bookType: 'xlsx', bookSST: false, type: 'binary'});
  let title = defaultTitle || '列表';
  saveAs(new Blob([s2ab(wbout)], {type: "application/octet-stream"}), title + ".xlsx")
}

3.按钮添加绑定事件

因为我是在 dropdown-item 中设置所以加上了 .native。

<el-dropdown-item @click.native="exportData">导出客户</el-dropdown-item>

4.方法调用

 //excel下载
    exportData() {
 	   // 因为分页是通过后端返回的，这里是保存当前的分页大小和页码
      this.searchFormData.oldPageSize=this.searchFormData.pageSize;
      this.searchFormData.oldPageNow=this.searchFormData.pageNow;
       // 然后将整表数据条数赋值给分页大小，页码赋值为1，加载表格数据
      this.searchFormData.pageNow=1;
      this.searchFormData.pageSize = this.tableData.total;
      this.loadTable();
       // 设置100ms的延时，不然就会打印了才调整表格数据
      setTimeout(() => {
        this.excelData = this.tableData.rows;  //导出数据赋值
        this.export2Excel(); //调用export2Excel函数，填写表头和对应字段
      },100);
    },
    //表格数据写入excel
    export2Excel() {
      var that = this;
      require.ensure([], () => {
        const {
          export_json_to_excel
        } = require("@/assets/excel/Export2Excel");
        const tHeader = ["客户名称", "联系电话", "订单金额", "未收款", "已收款"];
        const filterVal = ["name", "tel", " ", " ", " "];
        // 导出表格字段名
        const list = that.excelData;
        const data = that.formatJson(filterVal, list);
        // 导出的表格名称
        export_json_to_excel(tHeader, data, "客户信息汇总");
      });
        // 最后设置回原来的分页
      this.searchFormData.pageSize = this.searchFormData.oldPageSize;
      this.searchFormData.pageNow=this.searchFormData.oldPageNow;
      this.loadTable();
    },
    //格式转换
    formatJson(filterVal, jsonData) {
      return jsonData.map(v => filterVal.map(j => v[j]));
    },