ant-design-vue/components/tree/demo/line.md

#### 连接线 带连接线的树。 #### Tree With Line Tree With Line

<template>
  <a-tree
    showLine
    :defaultExpandedKeys="['0-0-0']"
    @select="onSelect"
  >
    <a-tree-node key="0-0">
      <span slot="title" style="color: #1890ff">parent 1</span>
      <a-tree-node title="parent 1-0" key="0-0-0">
        <a-tree-node title="leaf" key="0-0-0-0" />
        <a-tree-node title="leaf" key="0-0-0-1" />
        <a-tree-node title="leaf" key="0-0-0-2" />
      </a-tree-node>
      <a-tree-node title="parent 1-1" key="0-0-1">
        <a-tree-node title="leaf" key="0-0-1-0" />
      </a-tree-node>
      <a-tree-node title="parent 1-2" key="0-0-2">
        <a-tree-node title="leaf" key="0-0-2-0" />
        <a-tree-node title="leaf" key="0-0-2-1" />
      </a-tree-node>
    </a-tree-node>
  </a-tree>
</template>

<script>
export default {
  methods: {
    onSelect (selectedKeys, info) {
      console.log('selected', selectedKeys, info)
    },
  },
}
</script>