<el-table
      ref="table"
      border
      :data="list"
      default-expand-all
      row-key="id"
      :tree-props="{ children: 'children' }"
      @select="setSelectRows"
      @select-all="selectAll"
    >
      <el-table-column show-overflow-tooltip type="selection" />
      <el-table-column label="学员" prop="name" show-overflow-tooltip />
      <el-table-column label="手机号" prop="phone" show-overflow-tooltip />
  </el-table>

      const state = reactive({
        table: null,
      })

const setSelectRows = (selection) => {
          if(selection.length > 1){
            const del_row = selection.shift()
            state.table.toggleRowSelection(del_row,false) //设置这一行取消选中
         }
      }

      // 点击表头的全选复选框触发
      const selectAll = (selection) => {
          $baseMessage('只能单选哦！', 'error', 'vab-hey-message-error')
          state.table.clearSelection()
          return
        
      }