SOURCE

<script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.14/vue.js"></script>
<!-- 引入样式 -->
<link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css">
<!-- 引入组件库 -->
<script src="https://unpkg.com/element-ui/lib/index.js"></script>

<div id="app">
    
     <el-table
	    :data="tableData1"
	    style="width: 100%"
	    row-key="id"
	    border
	    lazy
	    :load="load"
	    :tree-props="{children: 'children', hasChildren: 'hasChildren'}" 
        @row-click="rowClick">
	    <el-table-column
	      prop="date"
	      label="日期"
	      width="180">
	    </el-table-column>
	    <el-table-column
	      prop="name"
	      label="姓名"
	      width="180">
	    </el-table-column>
	    <el-table-column
	      prop="address"
	      label="地址">
	    </el-table-column>
	  </el-table>
</div>
<style>
  .demo-table-expand {
    font-size: 0;
  }
  .demo-table-expand label {
    width: 90px;
    color: #99a9bf;
  }
  .demo-table-expand .el-form-item {
    margin-right: 0;
    margin-bottom: 0;
    width: 50%;
  }
</style>

<script>
  new Vue( {
      el: '#app',
    data() {
      return {
       tableData1: [{
		          id: 1,
		          date: '2016-05-02',
		          name: '王小虎',
		          address: '上海市普陀区金沙江路 1518 弄'
		        }, {
		          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',
		          hasChildren: true
		        }, {
		          id: 4,
		          date: '2016-05-03',
		          name: '王小虎',
		          address: '上海市普陀区金沙江路 1516 弄'
		        }]
      }
    },
    created:{
        let a={a:1,b:2}
        let b = a;
        console.log(a,b)
    },
    methods: {
         rowClick(row, column, event){
        top.console.log (event.target, event.currentTarget)
        if(event.currentTarget.querySelector('.el-table__expand-icon')){
                 event.currentTarget.querySelector('.el-table__expand-icon').click();
             }
      },
		load(tree, treeNode, resolve) {
		        setTimeout(() => {
		          resolve([
		            {
		              id: 31,
		              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'
		            }
		          ])
		        }, 1000)
		      },
    }
  })
</script>