使用Element的组件Table表格，当使用树形数据再配合上多选框，如下：

 会出现一种问题，点击左上方全选，只能够选中一级树节点，子节点无法被选中，如图所示：

想要实现点击全选就选中所有的表格，要另想办法，方法如下：
1、首先给table设置一个ref；
2、绑定一个@select-all方法； 

 3、定义一个变量，来识别全选框是否被选中，默认为未被选中；

checkedKeys: false,

4、@select-all绑定的方法如下，Element的Table表格中，select-all表示当用户手动勾选全选 Checkbox 时触发的事件 ，每次点击，checkedKeys就取反，对表格数据进行foreach循环，使多选框选中/取消选中的关键代码为：

 this.$refs.multipleTable.toggleRowSelection(row, flag);
flag=true多选框选中，flag=false取消选中
该方法不会影响@selection-change绑定的方法，若状态为全选，可以拿到全选的数据。

代码截图如下：

全部代码如下： 

<template>
  <div>
    <h1>树型数据+表格</h1>
    <el-table :data="tableData" style="width:80%;margin: 100px;" row-key="id" border default-expand-all
      @select-all="selectAll" ref="multipleTable" @selection-change="handleSelectionChange">
      <el-table-column type="selection" width="55">
      </el-table-column>
      <el-table-column prop="date" label="日期" sortable width="180">
      </el-table-column>
      <el-table-column prop="name" label="姓名" sortable width="180">
      </el-table-column>
      <el-table-column prop="address" label="地址" width="380">
      </el-table-column>
    </el-table>
  </div>
</template>
<script>
export default {
  nama: "Tree",
  data() {
    return {
      checkedKeys: false,
      tableData: [
        {
          id: 1,
          date: "2016-05-02",
          name: "王小虎",
          address: "上海市普陀区金沙江路 1518 弄",
          children: [],
        },
        {
          id: 2,
          date: "2016-05-04",
          name: "王小虎",
          address: "上海市普陀区金沙江路 1517 弄",
        },
        {
          id: 3,
          date: "2016-05-01",
          name: "王小虎",
          address: "上海市普陀区金沙江路 1519 弄",
          children: [
            {
              id: 31,
              date: "2016-05-01",
              name: "王小虎",
              address: "上海市普陀区金沙江路 1519 弄",
            },
            {
              id: 3531,
              date: "2016-05-01",
              name: "王小虎",
              address: "上海市普陀区金沙江路 1519 弄",
            },
            {
              id: 8931,
              date: "2016-05-01",
              name: "王小虎",
              address: "上海市普陀区金沙江路 1519 弄",
            },
            {
              id: 32,
              date: "2016-05-01",
              name: "王小虎",
              address: "上海市普陀区金沙江路 1519 弄",
              children: [
                {
                  id: 61,
                  date: "2016-05-01",
                  name: "王小虎",
                  address: "上海市普陀区金沙江路 1519 弄",
                },
                {
                  id: 42,
                  date: "2016-05-01",
                  name: "王小虎",
                  address: "上海市普陀区金沙江路 1519 弄",
                  children: [
                    {
                      id: 321,
                      date: "2016-05-01",
                      name: "王小虎33333",
                      address: "上海市普陀区金沙江路 1519 弄",
                    },
                  ],
                },
              ],
            },
          ],
        },
        {
          id: 4,
          date: "2016-05-03",
          name: "王小虎",
          address: "上海市普陀区金沙江路 1516 弄",
        },
      ],
    };
  },
  methods: {
    selectAll() {
      this.checkedKeys = !this.checkedKeys;
      this.splite(this.tableData, this.checkedKeys);
    },
    /**
     * 处理数据
     */
    splite(data, flag) {
      data.forEach((row) => {
        this.$refs.multipleTable.toggleRowSelection(row, flag);
        if (row.children != undefined) {
          this.splite(row.children);
        }
      });
    },
    handleSelectionChange(val){
        console.log(val);
        
    }
  }
};
</script>

上述方法只能用全选,选父级的话子级是不会选中的

下面这个方法，是选择父级子级可以选中,但是全选不能用

<template>
  <div>
    <el-table
      v-if="deptList.length > 0"
      v-loading="loading"
      :data="deptList"
      row-key="id"
      :default-expand-all="isExpandAll"
      :tree-props="{ children: 'children', hasChildren: 'hasChildren' }"
      @select-all="selectAll"
      ref="multipleTable"
      @selection-change="handleSelectionChange"
    >
      <el-table-column type="selection" :selectable="row => !row.disabled">
        <template slot-scope="scope">
          <el-checkbox v-model="scope.row.selected" @change="onRowSelectChange(scope.row)"></el-checkbox>
        </template>
      </el-table-column>
      <!-- 其他列定义 -->
    </el-table>
  </div>
</template>
 
<script>
export default {
  data() {
    return {
      deptList: [],
      loading: false,
      isExpandAll: false,
      checkedKeys: false
    };
  },
  methods: {
    selectAll() {
      this.checkedKeys = !this.checkedKeys;
      this.splite(this.deptList, this.checkedKeys);
    },
    splite(data, flag) {
      data.forEach((row) => {
        this.$refs.multipleTable.toggleRowSelection(row, flag);
        if (row.children && row.children.length) {
          this.splite(row.children, flag);
        }
      });
    },
    onRowSelectChange(row) {
      if (row.children && row.children.length > 0) {
        this.traverse(row.children, row.selected);
      }
    },
    traverse(data, checked) {
      data.forEach((row) => {
        this.$set(row, 'selected', checked);
        if (row.children && row.children.length > 0) {
          this.traverse(row.children, checked);
        }
      });
    },
    // 其他方法
  }
};
</script>