概览：给element组件添加上虚线，通过使用插件element-tree-line

参考连接：

参考别人的博客

安装插件：

# npm
npm install element-tree-line -S

# yarn
yarn add element-tree-line -S

main.js全局注册引入插件：

import { getElementLabelLine } from 'element-tree-line';
import 'element-tree-line/dist/style.css';
const ElementLabelLine = getElementLabelLine(h);
app.component(ElementLabelLine.name, ElementLabelLine);

el-tree组件封装：

<template>
    <el-tree ref="treeRef" class="tree-content" :data="props.treeData" node-key="id" :highlight-current="true"
        :props="props.defaultProps" icon="none" :current-node-key='0' default-expand-all :indent="props.treeIndent">
        <template #default="{ node, data }">
            <element-tree-line :node="node" :showLabelLine="false" :indent="props.treeIndent">
                <template v-slot:node-label>
                    <div class="com-tree">
                        <i v-if="data.children?.length > 0"
                            :class="node.expanded ? 'iconfont icon-pinleijianshao' : 'iconfont icon-pinleizengjia'"
                            class="tree-icon"></i>
                        <span class="com-tree-text" @click="nodeClick(data)">{{ node.label }}</span>
                    </div>
                </template>
            </element-tree-line>
        </template>
    </el-tree>
</template>

<script setup>
let props = defineProps({ treeData: Array, defaultProps: Object, treeIndent: Number });
const emits = defineEmits(['nodeClick']);
const nodeClick = (data) => {
    emits('nodeClick', data);
};
</script>

el-tree页面组件使用：

<el-scrollbar>
        <Tree 
            :treeData="data.treeData" 
            :defaultProps="defaultProps" 
            :treeIndent="data.treeIndent"
            @nodeClick="hanleNodeClick">
        </Tree>
</el-scrollbar>

 效果展示：