首先来总结element ui 官方文档的左侧菜单结构,带有el-submenu为子级节点,el-menu-item表示没有下级。当然,菜单不能写死，因为菜单也许不止两级,所以我们需要递归来实现。根据当前节点是否有下级去判断,如果有下级,则继续调用子级,直到没有下级为止,下面我贴上左侧菜单所有的代码:

请求数据格式

[
 {
 name: "首页",
 id: -1,
 icon: "el-icon-picture-outline-round",
 url: "/index",
 children: []
 },
 {
 name: "按钮",
 id: 20,
 icon: "el-icon-message-solid",
 url: "/button",
 children: []
 },
 {
 name: "测试1",
 id: 1,
 icon: "el-icon-s-claim",
 url: "",
 children: [
 {
 id: 4,
 parentid: 1,
 name: "测试1-1",
 icon: "el-icon-chat-dot-round",
 url: "",
 children: [
 {
 id: 8,
 parentid: 1,
 name: "测试1-1-1",
 icon: "el-icon-cloudy",
 url: "/test",
 children: []
 },
 {
 id: 9,
 parentid: 1,
 name: "测试1-1-2",
 icon: "el-icon-files",
 url: "/test1",
 children: []
 }
 ]
 },
 {
 id: 5,
 parentid: 1,
 name: "测试1-2",
 icon: "el-icon-shopping-cart-1",
 url: "/test3",
 children: []
 }
 ]
 },
 {
 name: "测试2",
 id: 2,
 icon: "el-icon-menu",
 url: "",
 children: [
 {
 id: 6,
 parentid: 2,
 name: "测试2-1",
 icon: "el-icon-folder-checked",
 url: "",
 children: []
 },
 {
 id: 7,
 parentid: 2,
 name: "测试2-2",
 icon: "el-icon-folder-remove",
 url: "",
 children: []
 }
 ]
 },
 {
 name: "测试3",
 id: 3,
 icon: "el-icon-monitor",
 url: "",
 children: []
 }
 ]

menu.vue

<template>
 <div class="menu">
 <div class="logo-con">
 <div class="title" v-show="!collapse">
 <span class="title__sider-title is-active">{{logo}}</span>
 </div>
 <div class="title" v-show="collapse">
 <span class="title__sider-title el-tag--mini">LG</span>
 </div>
 </div>
 <el-menu
 :background-color="backgroundColor"
 :text-color="textColor"
 :default-active="$route.meta.pageId"
 :collapse="collapse"
 >
 <template v-for="item in list">
 <router-link :to="item.url" :key="item.id" v-if="item.children.length===0">
 <el-menu-item :index="item.id.toString()">
 <i :class="item.icon"></i>
 <span slot="title">{{item.name}}</span>
 </el-menu-item>
 </router-link>
 <subMenu v-else :data="item" :key="item.id"></subMenu>
 </template>
 </el-menu>
 </div>
</template>

<script>
import subMenu from "./subMenu";
export default {
 name: "menuList",
 components: {
 subMenu
 },
 data() {
 return {
 collapse: false, //是否折叠
 list: [], //当行菜单数据源
 backgroundColor: "#304156", //导航菜单背景颜色
 textColor: "#BFCBD9", //导航菜单文字颜色
 logo: "LOGO" //logo
 };
 }
};
</script>

<style lang="scss" scoped>
.el-menu {
 border-right: none;
 a {
 text-decoration: none;
 }
}
.logo-con {
 height: px;
 padding: 10px;

 .title {
 position: relative;
 text-align: center;
 font-size: 20px;
 height: px;
 line-height: px;

 span {
 padding: 0 5px 0 0;
 color: #409eff;
 font-size: 20px;
 }
 }
}
</style>

submenu.vue

　　 这里有个知识点functional,不懂自行百度,文档地址: https://cn.vuejs.org/v2/guide/render-function.html#search-query-sidebar

5 <!--
 * @Description: 
 * @Author: PengYH
 * @Date: 2019-08-06
 -->
<template functional>
 <el-submenu :index="props.data.id.toString()">
 <template slot="title">
 <i :class="props.data.icon"></i>
 <span>{{props.data.name}}</span>
 </template>
 <template v-for="item in props.data.children">
 <router-link :to="item.url" :key="item.id" v-if="item.children.length===0">
 <el-menu-item class="subitem" :index="item.id.toString()">
 <i :class="item.icon"></i>
 <span slot="title">{{item.name}}</span>
 </el-menu-item>
 </router-link>
 <sub-menu v-else :data="item" :key="item.id"></sub-menu>
 </template>
 </el-submenu>
</template>
<script>
export default {
 name: "submenu",
 props: {
 data: [Array, Object]
 }
};
</script>
<style lang="scss" scoped>
.el-submenu {
 .el-menu-item {
 padding: 0;
 }
}
</style>

效果图

总结

以上所述是小编给大家介绍的vue element 生成无线级左侧菜单的实现代码，希望对大家有所帮助，如果大家有任何疑问欢迎给我留言，小编会及时会及时回复大家的！