前端将表格导出Excel -react项目

前言：主要用到的东西是:xlsx-style,之后进行二次封装，再引入使用
（代码实现并没有获取页面什么东西，是直接拿数据源进行处理出来，注释都在代码中！！！）
npm地址

一。将xlsx-style引入项目

npm install xlsx-style --save

二。将xlsx-style封装一下

/* eslint-disable */
import FileSaver from 'file-saver'
import XLSX from 'xlsx-style'

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")
}

export function export_json_to_excel({
  // title,
  multiHeader = [],
  header,
  data,
  filename,
  merges = [],
  autoWidth = true,
  bookType = 'xlsx'
} = {}) {
  /* original data */
  filename = filename || 'excel-list'
  data = [...data]
  data.unshift(header);
  // data.unshift(title);
  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': 200
        };
      }
      /*再判断是否为中文*/
      else if (val.toString().charCodeAt(0) > 255) {
        return {
          'wch': val.toString().length * 5
        };
      } else {
        return {
          'wch': val.toString().length * 3
        };
      }
    }))
    /*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] < colWidth[i][j]) {
          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 dataInfo = wb.Sheets[wb.SheetNames[0]];

  const borderAll = {  //单元格外侧框线
    top: {
      style: 'thin'
    },
    bottom: {
      style: 'thin'
    },
    left: {
      style: 'thin'
    },
    right: {
      style: 'thin'
    }
  };
  //给所以单元格加上边框
  for (var i in dataInfo) {
    if (i == '!ref' || i == '!merges' || i == '!cols' || i == 'A1') {

    } else {
      dataInfo[i + ''].s = {
        border: borderAll
      }
    }
  }

  var wbout = XLSX.write(wb, {
    bookType: bookType,
    bookSST: false,
    type: 'binary'
  });
  saveAs(new Blob([s2ab(wbout)], {
    type: "application/octet-stream"
  }), `${filename}.${bookType}`);
}

三。将封装好的xlsx-style进行使用

//-------------------引入封装的组件------------------------------------------------
import * as excelExport from '../../utils/Export2Excel'   


class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      data: [],
      source:[],
     //TA数据分红导出
      DetailColumns:[],
      DetailtableData:[],
      DTexcelHeader: [],  //
      DTexcelBody: [],  //
      DTfilterVal: [],  // 
      DTdate:'',
   
    }
  }
//----------------处理数据的函数 --------------------------------------------------
  dealwithDetailData(){
    const DetailColumns = [  //需要展示的表头
      {
        title: '第一列', //表头名字
        dataIndex: 'F_CODE',//对应的后端返回字段
        key: 'F_CODE',//react渲染的key值，可以和dataIndex一样
      },
      {
        title: '第二列',
        dataIndex: 'F_NAME',
        key: 'F_NAME',
      },
      {
        title: '第三列',
        dataIndex: 'R_DATE',
        key: 'R_DATE',
      },  
    ];    
    let DTexcelHeader = []
    let DTexcelBody = []
    let DTfilterVal = []

    DetailColumns.map(item => {
      if (!item.children) {
        DTexcelHeader.push(item.title)
        DTfilterVal.push(item.dataIndex)
      } else {
        item.children.map(itm => {
            DTexcelHeader.push(item.title + itm.title)
            DTfilterVal.push(itm.dataIndex)
        })
      }
    })

    this.state.DetailtableData.map(item => {
      for (const i in item) {
        if (item.hasOwnProperty(i) && item[i] == null) {
          item[i] = ''
        }
      }
      DTexcelBody.push(item)
    })        
    this.setState({
        DetailColumns,DTexcelHeader, DTexcelBody,DTfilterVal
    })
  };

  //excel导出数据进行格式化函数
  formatJson(DTfilterVal, jsonData) {
      return jsonData.map(v => DTfilterVal.map(j => v[j]));
  };


//---------------因为xlsx-style,比较大，所以在点击的时候再调用--------- 
    render(){
        return (
            <div>
                <Button icon="file-excel" key="confim" type="primary" size="large"
                        onClick={ ()=>excelExport.export_json_to_excel({
                        header:this.state.DTexcelHeader,  //表头
                        data:this.formatJson(this.state.DTfilterVal,this.state.DTexcelBody), //数据格式化
                        filename:`某某文件(${this.state.DTdate})`, //导出的名字
                        autoWidth: true,
                        bookType: "xlsx"
                    })
                }>
                        导出Excel
                </Button> 
            </div>
        )



    }
}