1. 先安装excel.js

      1. yarn add exceljs

    2. 在代码中引用 ```javascript const workbook = new ExcelJS.Workbook();

    // 生成sheet，冻结第一列、第一行 const sheet = workbook.addWorksheet(“Sheet 1”, {views: [{state: “frozen”, xSplit: 1, ySplit: 1}]}) 

    2. 3. 准备数据等 （建议先大致建立一个想要导出的excel，然后对比设置会比较方便）
    4. ![image.png](https://cdn.nlark.com/yuque/0/2021/png/886344/1637649748396-8814a59b-0fee-4721-88f4-0248b51670f0.png#clientId=ua9f12f21-a1a6-4&from=paste&height=132&id=u1d8ec795&margin=%5Bobject%20Object%5D&name=image.png&originHeight=132&originWidth=458&originalType=binary&ratio=1&size=10797&status=done&style=none&taskId=u5f1d7bb7-1619-4d5b-895b-695d3138cce&width=458)
    5. ```javascript
    6. const data = []
    8. // 创建表头 ，需要合并的单元格使用 null 代替
    9. data.push(["成绩统计表", null, null, null, null, null]);
    10. data.push(["序号", "姓名", "班级", "性别", "成绩", null]);
    11. data.push([null, null, null, null, "语文", "数学"]);
    13. //根据 null 合并单元格  （好像有点小问题，需要再调试调试）
    14. data.forEach((i, index) => {
    15.         sheet.addRow(i)
    16.         let isNull = false
    17.         let mergeObj = {}
    18.         if (index < 2) {
    19.           i.forEach((j, k) => {
    20.               if (j === null && !isNull && Object.keys(mergeObj).length === 0) {
    21.                 mergeObj.top = index + 1
    22.                 mergeObj.left = k
    23.                 isNull = true
    24.               } else if ((j && isNull) || (j === null && k === i.length - 1)) {
    25.                 isNull = false
    26.                 mergeObj.bottom = index + 1
    27.                 mergeObj.right = k
    28.                 sheet.mergeCells(mergeObj.top, mergeObj.left, mergeObj.bottom, mergeObj.right)
    29.                 mergeObj = {}
    30.               }
    31.             }
    32.           )
    33.         } else if (index === 2) {
    34.           i.forEach((j, k) => {
    35.             if (j === null) {
    36.               sheet.mergeCells(`${abc[k]}${index}:${abc[k]}${index + 1}`)
    37.             }
    38.           })
    39.         }
    40.       }
    41.     )
    43. //根据dataSource，往sheet中存放数据
    44.   const dataSource = [
    45.     {name: "张三", class: "一班", gender: "男", ChineseGrade: "78", MathGrade: "89"},
    46.     {name: "李四", class: "一班", gender: "男", ChineseGrade: "89", MathGrade: "78"},
    47.   ];
    48.   dataSource.forEach((i, index) => {
    49.     sheet.addRow([
    50.       index+1,
    51.       i.name,
    52.       i.class,
    53.       i.gender,
    54.       i.ChineseGrade,
    55.       i.MathGrade
    56.     ]);
    57.   });

    1. 修改表格样式等 ```javascript // 对每行、每行中的单元格设置行高、字体、边框等 sheet.eachRow({includeEmpty: true}, (row, rowNumber) => { //设置行高，顺便设置第二、第三行表头的字体等 if (rowNumber === 1) {

      1.  row.height = 50
      2.  row.eachCell((cell) => {
      3.    cell.font = {
      4.      name: '宋体',
      5.      size: 36,
      6.      bold: true
      7.    }
      8.  })

      } else if (rowNumber === 2 || rowNumber === 3) {

      1.  row.height = 20
      2.  row.eachCell((cell, cellNumber) => {
      3.    if ((cellNumber > 9 && cellNumber < 12) || (cellNumber > 12 && cellNumber < 16) || (cellNumber > 20 && cellNumber < 26)) {
      4.      cell.font = {
      5.        name: '宋体',
      6.        size: rowNumber === 2 ? 16 : 14,
      7.        bold: rowNumber === 2
      8.      }
      9.    } else {
      10.      cell.font = {
      11.        name: '宋体',
      12.        size: 16,
      13.        bold: true
      14.      }
      15.    }
      16.  })

      } else {

      1.  //通用行高
      2.  row.height = 25

      }

      //遍历所有包括空的单元格，设置样式等 row.eachCell({includeEmpty: true}, (cell) => {

      1.  cell.alignment = {vertical: 'middle', horizontal: 'center', wrapText: true}  //居中对齐，自动换行
      2.  cell.border = {
      3.    top: {style: 'thin'},
      4.    left: {style: 'thin'},
      5.    bottom: {style: 'thin'},
      6.    right: {style: 'thin'}
      7.  }
      8.  if (rowNumber > 3) { // 对第三行以上的设置字题
      9.    cell.font = {
      10.      name: '宋体',
      11.      size: 14
      12.    }
      13.  }

      }) })

    //设置每一列的列宽 sheet.columns = [ {width:8}, //序号 {width:10}, //姓名 {width:10}, //班级 {width:8}, //性别 {width:10}, //语文 {width:10}, //数学 ]

    2. 5. 导出文件
    3. ```javascript
    4. // 导出文件
    5.   const writeFile = (fileName: string, content: Buffer) => {
    6.     let a = document.createElement("a");
    7.     let blob = new Blob([content], {type: "text/plain"});
    9.     a.download = fileName;
    10.     a.href = URL.createObjectURL(blob);
    12.     a.click();
    13.   };
    14.   workbook.xlsx.writeBuffer().then((buffer) => {
    15.     // @ts-ignore
    16.     return writeFile(`成绩统计表.xlsx`, buffer);
    17.   });