目录，三个文件

 

tree-node.vue

<template>
  <div class="tree-node-container">
    <node-content></node-content>
    <div
      class="tree-node-children"
      :style="{
        paddingLeft: indent
      }"
      v-if="nextShow">
      <tree-node
        v-for="(child, idx) of nodeData.children"
        :nodeData="child"
        :indent="indent"
        :key="idx">
      </tree-node>
    </div>
  </div>
</template>

<script>

export default {
  name: 'tree-node',
  props: {
    nodeData: {
      type: Object,
      required: true
    }
  },
  components: {
    'node-content': {
      render (h) {

        let slot = this.$parent.tree.$slots.default
        let { nodeData, parentData, level, nextShow } = this.$parent
        return (slot ? slot({ parentData, data: nodeData, level, nextShow }) : '<div>未定义插槽内容</div>')
      }
    }
  },
  data () {
    return {
      tree: false,
      level: 0,
      parentData: null,
      childrenShow: true,
      indent: undefined
    }
  },
  computed: {
    nextShow () {
      return this.nodeData.children && this.nodeData.children.length && this.childrenShow
    }
  },
  created () {
    let parent = this.$parent
    if (parent.isTree) {
      this.level = 1
    } else {
      this.level = parent.level + 1
      this.parentData = parent.nodeData
    }
    while (parent && !parent.isTree) {
      parent = parent.$parent
    }
    this.tree = parent
    this.indent = this.tree.indent
    console.log('this.nodeData',this.nodeData)
    this.tree.registerNodeComponent(this.nodeData.id, this)

  },
  beforeDestroy () {
    console.log('pppppppppppppppppppppp')
    this.tree.removeNodeComponent(this.nodeData.id)
  },
  mounted(){
    // this.tree.removeNodeComponent(this.nodeData.id)
  },
  methods: {
    showChildren (show) {
      this.childrenShow = show
    }
  }
}
</script>

 tree.vue

<template>
  <div class="tree-container">
    <tree-node
      v-for="(nodeData, idx) of treeData"
      :nodeData="nodeData"
      :key="idx">
    </tree-node>
  </div>
</template>

<script>
import treeNode from './tree-node'

export default {
  components: {
    treeNode
  },
  props: {
    treeData: {
      type: Array,
      requied: true
    },
    indent: {
      type: String,
      default: '20px'
    }
  },
  data () {
    return {
      isTree: true,
      level: 0,
      componentMap: {},
      width:'200px',
      height:'500px'

    }
  },
  methods: {
    registerNodeComponent (id, component) {
      this.componentMap[id] = component
    },
    removeNodeComponent (id) {
      console.log('this.componentMap',this.componentMap,id)
      this.componentMap[id] = undefined
    },
    showChildren (id, show) {
      this.componentMap[id] && this.componentMap[id].showChildren(show)
    }

  },
  mounted(){
    console.log('this',this.componentMap)
  }
}
</script>

<style  scoped>
.tree-container{
   text-align:left
}

</style>

使用

Tree.vue

<template>
  <div class="tree-page">
    <div class="tree">
      <tree :treeData="treeData" ref="tree">
        <template v-slot="{ parentData, data, level, nextShow }">
          <div class="node-slot">

            <div class="slot-content"
            :class="{active_content:activeId === data.id}"
             @click="clickTitle(data)">
              <img :src="data.icon" />
              <span class="node-title">{{ data.title }}</span>

            </div>
            <div class="expand">
              <div
                class="expand-btn"
                @click.stop="clickExpand(data, nextShow)"
                v-if="data.children && data.children.length"
              >
              <span v-if="nextShow">+</span>
              <span v-else>-</span>

              </div>

            </div>
          </div>
        </template>
      </tree>
    </div>
  </div>
</template>

<script>
import tree from "../components/tree/tree.vue";

export default {
  name: "app",
  components: {
    tree,
  },
  data() {
    return {
      treeData:[
          {
            title: "第一个",
            icon: "icons/上升.svg",
            id: "1",
            children: [
              { title: "第一/1个", icon: "icons/上升.svg", id: "1-1" },
              {
                title: "第一/2个",
                icon: "icons/上升.svg",
                id: "1-2",
                children: [
                  { title: "第一ce个", icon: "icons/上升.svg", id: "1-2-1" },
                ],
              },
            ],
          },
          { title: "第二个", icon: "icons/上升.svg", id: "2" },
          { title: "第三个", icon: "icons/上升.svg", id: "3" },
        ],
      nodeId: 100,
      activeId:''
    };
  },
  methods: {
    clickExpand(data, nextShow) {
      this.$refs.tree.showChildren(data.id, !nextShow);
    },

    clickTitle(data){
      this.activeId = data.id
    }
  },
};
</script>
<style scoped>
.tree-page {
  display: flex;
  width: 200px;
}
.tree {
  flex: auto;
  overflow: auto;
  padding: 20px;
}
.node-slot {
  display: flex;
  align-items: center;
  line-height: 2;
  font-size: 20px;
}
.expand {
  flex-shrink: 0;
  width: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: 2px;
}
.expand-btn {
  font-size: 24px;
  color: #888;
  line-height: 1;
  border-radius: 50%;
  cursor: pointer;
}
.dot {
  border-radius: 50%;
  border: 3px solid #aaa;
  width: 0;
}
.slot-content {
  flex: auto;
  padding: 0 4px;
}
.slot-content:hover {
  background: rgba(64, 158, 255, 0.2);
}
.node-title {
  vertical-align: middle;
}
.node-menu-list {
  font-size: 14px;
  vertical-align: middle;
  margin-left: 10px;
}
.menu {
  padding: 2px 6px;
  margin: 0 2px;
}
.active_content{
  color: red;
  background: rgba(64, 158, 255, 0.2);
}
img{
  width: 16px;
  height:16px;
  background-color: blue;
}
</style>

以上参照了这位的博客Vue树组件实现 - 沐码小站

下面是用element 抽屉封装的，感觉没那么灵活

两个文件

menuChild.vue 

<template>
  <el-collapse class="coll-wrap">
    <div
      v-for="(item, i) in list"
      :key="item.id"
      :style="{
        'padding-left': deep + '0px',
      }"
      @click="menuClick(item)"
    >
      <el-collapse-item v-if="item.children" :title="item.title" :name="i">
        <template #title>
          <img :src="item.icon" />
          <span> {{ item.title }}</span>
        </template>
        <SubMenu
          :labelData="labelData"
          @updateLabel="updateLabel"
          :deep="deep + 1"
          v-if="item.children"
          :list="item.children"
        ></SubMenu>
      </el-collapse-item>
      <div class="item" :class="{ active: labelData == item.id }" v-else>
        <img :src="item.icon" /><span> {{ item.title }}</span>
      </div>
    </div>
  </el-collapse>
</template>

<script>
// import SubMenu from "./menu.vue"
export default {
  name: "SubMenu",
  data() {
    return {
      activeName: "",
      // list:[
      //   {title:'第一个',icon:"icons/上升.svg",id:'1',children:[
      //     {title:'第一/1个',icon:"icons/上升.svg",id:'1-1'},
      //     {title:'第一/2个',icon:"icons/上升.svg",id:'1-2'}
      //   ]},
      //   {title:'第二个',icon:"icons/上升.svg",id:'2'},
      //   {title:'第三个',icon:"icons/上升.svg",id:'3'}
      // ]
    };
  },
  props: {
    list: {
      type: Array,
      default() {
        return [
          {
            title: "第一个",
            icon: "icons/上升.svg",
            id: "1",
            children: [
              { title: "第一/1个", icon: "icons/上升.svg", id: "1-1" },
              {
                title: "第一/2个",
                icon: "icons/上升.svg",
                id: "1-2",
                children: [
                  { title: "第一ce个", icon: "icons/上升.svg", id: "1-2-1" },
                ],
              },
            ],
          },
          { title: "第二个", icon: "icons/上升.svg", id: "2" },
          { title: "第三个", icon: "icons/上升.svg", id: "3" },
        ];
      },
    },

    labelData: {
      type: String,
      default() {
        return "";
      },
    },
    deep: {
      type: Number,
      default() {
        return 0;
      },
    },
  },
  // components:{
  // SubMenu
  // },
  mounted() {
    console.log(this.list);
  },
  methods: {
    updateLabel(item) {
      this.$emit("updateLabel", item);
    },
    menuClick(item) {
      if (!item.children) {
        this.activeName = item.id;
        console.log("item", item);
        this.$emit("updateLabel", item);
      }
    },
  },
};
</script>

<style scoped>
.coll-wrap /deep/ .el-collapse-item__content {
  padding-bottom: 0 !important;
}
.coll-wrap /deep/ .el-collapse-item__wrap {
  border: 0 !important;
}
.item {
  padding: 15px 0;
  background-color: aqua;
}
.active {
  background-color: aliceblue;
}
img {
  width: 16px;
  height: 16px;
  background-color: blue;
}
.el-collapse {
  border: 0 !important;
  background-color: aqua;
}
.el-collapse-item /deep/ .el-collapse-item__header {
  border: 0 !important;
  background-color: aqua;
}
</style>

menu.vue

<template>
<MenuChild
class="my_menu"
:style="{
width:width,
height:height,

}"
:labelData="labelData"
@updateLabel = "updateLabel"
></MenuChild>
</template>

<script>
import MenuChild from "./menuChild.vue"
export default {
data(){
  return{
    labelData:'',
    width:'200px',
      height:'500px'
  }
},
components:{
  MenuChild

},
methods:{
  updateLabel(item){
    console.log(item)
    this.labelData = item.id
  }
}
}
</script>

<style scoped>
.my_menu{
  background-color: aqua;
}
</style>