el-table合并单元格

1.固定合并

• 官方挺提供的合并具体某行列的方法:el-table合并行或列
• 通过给table传入span-method方法可以实现合并行或列，方法的参数是一个对象，里面包含当前行row、当前列column、当前行号rowIndex、当前列号columnIndex四个属性。
  该函数可以返回一个包含两个元素的数组，第一个元素代表rowspan，第二个元素代表colspan。 也可以返回一个键名为rowspan和colspan的对象。

<template>
  <div>
    <el-table
      :data="tableData"
      :span-method="arraySpanMethod"
      border
      style="width: 100%">
      <el-table-column
        prop="id"
        label="ID"
        width="180">
      </el-table-column>
      <el-table-column
        prop="name"
        label="姓名">
      </el-table-column>
      <el-table-column
        prop="amount1"
        sortable
        label="数值 1">
      </el-table-column>
      <el-table-column
        prop="amount2"
        sortable
        label="数值 2">
      </el-table-column>
      <el-table-column
        prop="amount3"
        sortable
        label="数值 3">
      </el-table-column>
    </el-table>
    <el-table
      :data="tableData"
      :span-method="objectSpanMethod"
      border
      style="width: 100%; margin-top: 20px">
      <el-table-column
        prop="id"
        label="ID"
        width="180">
      </el-table-column>
      <el-table-column
        prop="name"
        label="姓名">
      </el-table-column>
      <el-table-column
        prop="amount1"
        label="数值 1（元）">
      </el-table-column>
      <el-table-column
        prop="amount2"
        label="数值 2（元）">
      </el-table-column>
      <el-table-column
        prop="amount3"
        label="数值 3（元）">
      </el-table-column>
    </el-table>
  </div>
</template>
<script>
  export default {
    data() {
      return {
        tableData: [{
          id: '12987122',
          name: '王小虎',
          amount1: '234',
          amount2: '3.2',
          amount3: 10
        }, {
          id: '12987123',
          name: '王小虎',
          amount1: '165',
          amount2: '4.43',
          amount3: 12
        }, {
          id: '12987124',
          name: '王小虎',
          amount1: '324',
          amount2: '1.9',
          amount3: 9
        }, {
          id: '12987125',
          name: '王小虎',
          amount1: '621',
          amount2: '2.2',
          amount3: 17
        }, {
          id: '12987126',
          name: '王小虎',
          amount1: '539',
          amount2: '4.1',
          amount3: 15
        }]
      };
    },
    methods: {
      arraySpanMethod({ row, column, rowIndex, columnIndex }) {
        if (rowIndex % 2 === 0) {
          if (columnIndex === 0) {
            return [1, 2];
          } else if (columnIndex === 1) {
            return [0, 0];
          }
        }
      },
      objectSpanMethod({ row, column, rowIndex, columnIndex }) {
        if (columnIndex === 0) {
          if (rowIndex % 2 === 0) {
            return {
              rowspan: 2,
              colspan: 1
            };
          } else {
            return {
              rowspan: 0,
              colspan: 0
            };
          }
        }
      }
    }
  };
</script>

运行效果：

• 缺点：这种只适合写死的数据和固定的表格行列，无法动态判断单元格数据是否相等再合并；

2. 动态合并相同数据单元格（所有列）

• 可以对所有相同数据的列，进行动态合并
• 此方法适合需要合并所有的相同数据的单元格

<template>
  <div>
    <el-table
      :data="tableData"
      :span-method="objectSpanMethod"
      border
      :header-cell-style="{ textAlign: 'center', backgroundColor: '#F5F7FA' }"
    >
      <el-table-column prop="School" label="学校" align="center">
      </el-table-column>
      <el-table-column prop="Grade" label="年级" align="center" />
      <el-table-column prop="Class" label="班级" align="center" />
      <el-table-column prop="Name" label="姓名" align="center" />
      <el-table-column prop="Chinese" label="语文" align="center" />
      <el-table-column prop="Math" label="数学" align="center" />
      <el-table-column prop="English" label="英语" align="center" />
    </el-table>
  </div>
</template>
<script>
export default {
  data() {
    return {
      // 存放所有的表头 一定要与tableData一致
      colFields: [
        "School",
        "Grade",
        "Class",
        "Name",
        "Chinese",
        "Math",
        "English",
      ],
      spanArr: [], //存储合并单元格的开始位置
      // 表格数据
      tableData: [
        // 一年级
        {
          School: "第一小学",
          Grade: "1年级",
          Class: "1班",
          Name: "张三",
          Chinese: "90",
          Math: "100",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "1年级",
          Class: "2班",
          Name: "李四",
          Chinese: "90",
          Math: "85",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "1年级",
          Class: "3班",
          Name: "王五",
          Chinese: "79",
          Math: "100",
          English: "80",
        },
        // 二年级
        {
          School: "第一小学",
          Grade: "2年级",
          Class: "1班",
          Name: "赵六",
          Chinese: "95",
          Math: "100",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "2年级",
          Class: "2班",
          Name: "钱八",
          Chinese: "98",
          Math: "85",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "2年级",
          Class: "3班",
          Name: "陈九",
          Chinese: "79",
          Math: "100",
          English: "80",
        },
        // 三年级
        {
          School: "第一小学",
          Grade: "3年级",
          Class: "1班",
          Name: "黄十",
          Chinese: "91",
          Math: "88",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "3年级",
          Class: "2班",
          Name: "魏一",
          Chinese: "90",
          Math: "86",
          English: "87",
        },
        {
          School: "第一小学",
          Grade: "3年级",
          Class: "3班",
          Name: "杨二",
          Chinese: "79",
          Math: "99",
          English: "80",
        },
      ],
    };
  },
  methods: {
    /**
     * 分析每一列，找出相同的
     * @param data
     */
    getSpanArr() {
      for (let i = 0; i < this.tableData.length; i++) {
        let row = i;
        // let col = i % this.colCount;
        if (row === 0) {
          // i 表示行 j表示列
          for (let j = 0; j < this.colFields.length; j++) {
            this.spanArr[i * this.colFields.length + j] = {
              rowspan: 1,
              colspan: 1,
            };
          }
        } else {
          for (let j = 0; j < this.colFields.length; j++) {
            // 当前和上一次的一样
            // 1. 合并所有列的相同数据单元格
            if (
              this.tableData[row][this.colFields[j]] ===
              this.tableData[row - 1][this.colFields[j]]
            ) {
              let beforeItem =
                this.spanArr[(row - 1) * this.colFields.length + j];
              this.spanArr[row * this.colFields.length + j] = {
                rowspan: 1 + beforeItem.rowspan, // 合并几行
                colspan: 1, // 合并几列,我这里只是跨行合并,不跨列合并,所以用的1
              };
              beforeItem.rowspan = 0;
              beforeItem.colspan = 0;
            } else {
              // rowspan 和 colspan 都为1表格此单元格不合并
              this.spanArr[row * this.colFields.length + j] = {
                rowspan: 1,
                colspan: 1,
              };
            }
          }
        }
      }
      // 对数据进行倒序
      let stack = [];
      for (let i = 0; i < this.colFields.length; i++) {
        for (let j = 0; j < this.tableData.length; j++) {
          // console.log("i=" + i + " j=" + j);
          // i 表示列 j表示行
          if (j === 0) {
            if (this.spanArr[j * this.colFields.length + i].rowspan === 0) {
              stack.push(this.spanArr[j * this.colFields.length + i]);
            }
          } else {
            if (this.spanArr[j * this.colFields.length + i].rowspan === 0) {
              stack.push(this.spanArr[j * this.colFields.length + i]);
            } else {
              stack.push(this.spanArr[j * this.colFields.length + i]);
              while (stack.length > 0) {
                let pop = stack.pop();
                let len = stack.length;
                this.spanArr[(j - len) * this.colFields.length + i] = pop;
              }
            }
          }
        }
      }
      // console.log(this.spanArr);
    },
    objectSpanMethod({ row, column, rowIndex, columnIndex }) {
      // console.log(this.spanArr[rowIndex * this.colFields.length + columnIndex]);
      return this.spanArr[rowIndex * this.colFields.length + columnIndex];
    },
  },
  mounted() {
    this.getSpanArr();
  },
};
</script>
<style lang="scss" scoped></style>

效果:

我们可以看到，所有列，只要数据相同的单元格都被合并了，包括我不想合并的单元格，这时候就要指定合并的列了

3. 动态合并相同数据单元格（指定列）

• 只需要加个if判断即可指定要合并哪些列

// 这里只放了部分代码,除了加了个if,其他代码和上面的一样
 getSpanArr() {
      for (let i = 0; i < this.tableData.length; i++) {
        let row = i;
        // let col = i % this.colCount;
        if (row === 0) {
          // i 表示行 j表示列
          for (let j = 0; j < this.colFields.length; j++) {
            this.spanArr[i * this.colFields.length + j] = {
              rowspan: 1,
              colspan: 1,
            };
          }
        } else {
          for (let j = 0; j < this.colFields.length; j++) {
            // 当前和上一次的一样
            //  合并所有列的相同数据单元格
            if (
              this.colFields[j] == "School" ||
              this.colFields[j] == "Grade" ||
              this.colFields[j] == "Class"
            ) { // 指定合并哪些列
              if (
                this.tableData[row][this.colFields[j]] ===
                this.tableData[row - 1][this.colFields[j]]
              ) {
                let beforeItem =
                  this.spanArr[(row - 1) * this.colFields.length + j];
                this.spanArr[row * this.colFields.length + j] = {
                  rowspan: 1 + beforeItem.rowspan,
                  colspan: 1,
                };
                beforeItem.rowspan = 0;
                beforeItem.colspan = 0;
              } else {
                // rowspan 和 colspan 都为1表格此单元格不合并
                this.spanArr[row * this.colFields.length + j] = {
                  rowspan: 1,
                  colspan: 1,
                };
              }
            }
          }
        }
      }

效果:
这样就只合并了我们指定的那几列了

4. 动态合并相同数据单元格（指定列+合并条件）

有时候我们会遇到不想合并的单元格，比如下面这种情况：

按常理来说，不同小学的数据应该是不做合并才对，正确是这种：

这时候就需要加上一些自定义的合并条件了：

getSpanArr() {
      for (let i = 0; i < this.tableData.length; i++) {
        let row = i;
        // let col = i % this.colCount;
        if (row === 0) {
          // i 表示行 j表示列
          for (let j = 0; j < this.colFields.length; j++) {
            this.spanArr[i * this.colFields.length + j] = {
              rowspan: 1,
              colspan: 1,
            };
          }
        } else {
          for (let j = 0; j < this.colFields.length; j++) {
            // 当前和上一次的一样
            //  合并所有列的相同数据单元格
            if (
              this.colFields[j] == "School" ||
              this.colFields[j] == "Grade" ||
              this.colFields[j] == "Class"
            ) { // 指定合并哪些列
              if (
                this.tableData[row]["School"] !==
                  this.tableData[row - 1]["School"]
              ) { // 哪些不合并:School不一样的,不合并
                this.spanArr[row * this.colFields.length + j] = {
                  rowspan: 1,
                  colspan: 1,
                };
              } else if (
                this.tableData[row][this.colFields[j]] ===
                this.tableData[row - 1][this.colFields[j]]
              ) {
                let beforeItem =
                  this.spanArr[(row - 1) * this.colFields.length + j];
                this.spanArr[row * this.colFields.length + j] = {
                  rowspan: 1 + beforeItem.rowspan,// 合并几列
                  colspan: 1,// 合并几行
                };
                beforeItem.rowspan = 0;
                beforeItem.colspan = 0;
              } else {
                // rowspan 和 colspan 都为1表格此单元格不合并
                this.spanArr[row * this.colFields.length + j] = {
                  rowspan: 1,
                  colspan: 1,
                };
              }
            }
          }
        }
      }
      // console.log(this.spanArr);
    },

这时候再看，就是我们想要的效果了

完整代码

最后附完整代码：

<template>
  <div>
    <el-table
      :data="tableData"
      :span-method="objectSpanMethod"
      border
      :header-cell-style="{ textAlign: 'center', backgroundColor: '#F5F7FA' }"
    >
      <el-table-column prop="School" label="学校" align="center">
      </el-table-column>
      <el-table-column prop="Grade" label="年级" align="center" />
      <el-table-column prop="Class" label="班级" align="center" />
      <el-table-column prop="Name" label="姓名" align="center" />
      <el-table-column prop="Chinese" label="语文" align="center" />
      <el-table-column prop="Math" label="数学" align="center" />
      <el-table-column prop="English" label="英语" align="center" />
    </el-table>
  </div>
</template>
<script>
export default {
  data() {
    return {
      // 存放所有的表头 一定要与tableData一致
      colFields: [
        "School",
        "Grade",
        "Class",
        "Name",
        "Chinese",
        "Math",
        "English",
      ],
      spanArr: [], //存储合并单元格的开始位置
      // 表格数据
      tableData: [
        // 一年级
        {
          School: "第一小学",
          Grade: "1年级",
          Class: "1班",
          Name: "张三",
          Chinese: "90",
          Math: "100",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "1年级",
          Class: "1班",
          Name: "张伟",
          Chinese: "90",
          Math: "99",
          English: "89",
        },
        {
          School: "第一小学",
          Grade: "1年级",
          Class: "2班",
          Name: "李四",
          Chinese: "90",
          Math: "85",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "1年级",
          Class: "3班",
          Name: "王五",
          Chinese: "79",
          Math: "100",
          English: "80",
        },
        // 二年级
        {
          School: "第一小学",
          Grade: "2年级",
          Class: "1班",
          Name: "赵六",
          Chinese: "95",
          Math: "100",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "2年级",
          Class: "2班",
          Name: "钱八",
          Chinese: "98",
          Math: "85",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "2年级",
          Class: "3班",
          Name: "陈九",
          Chinese: "79",
          Math: "100",
          English: "100",
        },
        // 三年级
        {
          School: "第一小学",
          Grade: "3年级",
          Class: "1班",
          Name: "黄十",
          Chinese: "91",
          Math: "88",
          English: "80",
        },
        {
          School: "第一小学",
          Grade: "3年级",
          Class: "2班",
          Name: "魏一",
          Chinese: "90",
          Math: "86",
          English: "87",
        },
        {
          School: "第一小学",
          Grade: "3年级",
          Class: "3班",
          Name: "杨二",
          Chinese: "79",
          Math: "99",
          English: "80",
        },
        // 第二小学
        {
          School: "第二小学",
          Grade: "3年级",
          Class: "3班",
          Name: "袁零",
          Chinese: "79",
          Math: "99",
          English: "80",
        },
      ],
    };
  },
  methods: {
    /**
     * 分析每一列，找出相同的
     * @param data
     */
    getSpanArr() {
      for (let i = 0; i < this.tableData.length; i++) {
        let row = i;
        // let col = i % this.colCount;
        if (row === 0) {
          // i 表示行 j表示列
          for (let j = 0; j < this.colFields.length; j++) {
            this.spanArr[i * this.colFields.length + j] = {
              rowspan: 1,
              colspan: 1,
            };
          }
        } else {
          for (let j = 0; j < this.colFields.length; j++) {
            // 当前和上一次的一样
            //  合并所有列的相同数据单元格
            if (
              this.colFields[j] == "School" ||
              this.colFields[j] == "Grade" ||
              this.colFields[j] == "Class"
            ) { // 指定合并哪些列
              if (
                this.tableData[row]["School"] !==
                  this.tableData[row - 1]["School"]
              ) { // 哪些不合并:School不一样的,不合并
                this.spanArr[row * this.colFields.length + j] = {
                  rowspan: 1,
                  colspan: 1,
                };
              } else if (
                this.tableData[row][this.colFields[j]] ===
                this.tableData[row - 1][this.colFields[j]]
              ) {
                let beforeItem =
                  this.spanArr[(row - 1) * this.colFields.length + j];
                this.spanArr[row * this.colFields.length + j] = {
                  rowspan: 1 + beforeItem.rowspan,// 合并几列
                  colspan: 1,// 合并几行
                };
                beforeItem.rowspan = 0;
                beforeItem.colspan = 0;
              } else {
                // rowspan 和 colspan 都为1表格此单元格不合并
                this.spanArr[row * this.colFields.length + j] = {
                  rowspan: 1,
                  colspan: 1,
                };
              }
            }
          }
        }
      }
      // 对数据进行倒序
      let stack = [];
      for (let i = 0; i < this.colFields.length; i++) {
        for (let j = 0; j < this.tableData.length; j++) {
          // console.log("i=" + i + " j=" + j);
          // i 表示列 j表示行
          if (j === 0) {
            if (this.spanArr[j * this.colFields.length + i].rowspan === 0) {
              stack.push(this.spanArr[j * this.colFields.length + i]);
            }
          } else {
            if (this.spanArr[j * this.colFields.length + i].rowspan === 0) {
              stack.push(this.spanArr[j * this.colFields.length + i]);
            } else {
              stack.push(this.spanArr[j * this.colFields.length + i]);
              while (stack.length > 0) {
                let pop = stack.pop();
                let len = stack.length;
                this.spanArr[(j - len) * this.colFields.length + i] = pop;
              }
            }
          }
        }
      }
      // console.log(this.spanArr);
    },
    objectSpanMethod({ row, column, rowIndex, columnIndex }) {
      // console.log(this.spanArr[rowIndex * this.colFields.length + columnIndex]);
      return this.spanArr[rowIndex * this.colFields.length + columnIndex];
    },
  },
  mounted() {
    this.getSpanArr();
  },
};
</script>
<style lang="scss" scoped></style>

参考:https://blog.csdn.net/u010735120/article/details/122184493