前端如何导入、导出 excel文件

1. 导入详解
2. 导出详解

导入详解

前端完成 导入上传excel文件（一般只会向后端发送文件，这里允许添加额外参数）

<!-- 导入对话框 -->
<el-dialog :visible.sync="isVisible" title="选择excel文件" width="30%" @close="changeVisible(false)">
    <el-upload
        ref="upload"
        :multiple="false"
        list-type="text"
        :file-list="fileList"
        :show-file-list="true"
        :auto-upload="false"
        <!-- 这个必须设置成false，否则文件选择后就会自动上传，而无法继续传额外参数 -->
        class="editor-slide-upload"
        :on-success="handleSuccess"
        :action="uploadUrl"
        :limit="1"
        accept=".xlsx"
      >
        <el-button size="small" type="primary">上传文件</el-button>
   </el-upload>
   <el-date-picker v-model="uploadDate" type="month" placeholder="选择时间" value-format="yyyy-M" />
   <span slot="footer" class="dialog-footer">
        <el-button @click="changeVisible(false)">取消</el-button>
        <el-button type="primary" @click="handleSubmit">确定</el-button>
   </span>
</el-dialog>
<script>
handleSubmit() {
     if (this.$refs.upload.$children[0].fileList.length && this.uploadDate !== '') {
	 //时间、文件都不为空，可以上传
        this.$refs.upload.submit()
	//手动上传通过上面这种方式
      } else {
        this.$message.warning('缺乏文件或时间')
      }
}
</script>

导出详解

方式1：后端给接口，前端创建临时下载链接

// 由前端创建一个临时下载链接，自定义下载指定接口数据
export2excel() {
    callInterface.then(res => {
        var blob = new Blob([res.data], { type: 'application/vnd.ms-excel' }); // type这里表示xls类型
        var downloadElement = document.createElement('a'); // 产生下载连接
        const objectUrl = URL.createObjectURL(blob); // 创建一个临时url
        downloadElement.href = objectUrl; // 挂载
	// 获取文件名
        downloadElement.download = decodeURI(res.headers['content-disposition'].split(';')[1].split('=')[1].split("''")[1]) 
        downloadElement.click(); // 点击下载
      });
    },

方式2：将一个表格(如el-form)导出为excel文件，不需要后端参与

//目录结构
---------- xxx.vue
---------- Export2Excel.js
---------- Blob.js

xxx.vue 文件

formatJson(filterVal, jsonData) {
// 遍历表格数据 ，并将其 JSON 格式化
    return jsonData.map(v => filterVal.map(j => {
      if (j === 'dept') {
        return [v['firstLevelDept'], v['secondLevelDept'], v['thirdLevelDept']].join('_')
      } else if (j === 'resourceDetailMap') {
         return JSON.stringify(v['resourceDetailMap'])
      }
      return v[j]
    }
  ))
}
export2excel() {
     require.ensure([], () => {
     const { exportJsonToExcel } = require('./Export2Excel.js');
	 // 导出的excel表--列头的名字，与下面的变量名一一对应
     const tHeader = ['时间', '用户名', '密码', '年龄' , '分数'];
	 // 这里为 el-form 组件各列 绑定的变量名，不一定是所有的
     const filterVal = ['date', 'username', 'psd', 'age', 'grade'];
     const list = this.dataList;  // el-form 绑定的数据源
     const data = this.formatJson(filterVal, list);
     exportJsonToExcel(tHeader, data, '导出的 excel 文件名');
    })
}

Export2Excel.js 文件

// npm install script-loader@0.7.2

require('script-loader!file-saver');
require('./Blod');
require('script-loader!xlsx/dist/xlsx.core.min');
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);
  console.log('a')
  var oo = generateArray(theTable);
  var ranges = oo[1];

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

  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")
}

function formatJson(jsonData) {
  console.log(jsonData)
}
export function exportJsonToExcel(th, jsonData, defaultTitle) {

  /* original data */

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

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


  /* 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'});
  var title = defaultTitle || '列表'
  saveAs(new Blob([s2ab(wbout)], {type: "application/octet-stream"}), title + ".xlsx")
}

Blob.js 文件

(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));