Vue.js uses Element-ui to implement the navigation menu

<template>
    <div class="app">
        <el-container>
        <el-aside>
            <navmenu></navmenu>
        </el-aside>
        <el-main>
            <router-view></router-view>
        </el-main>
        </el-container>
    </div>
</template>
<script>
import navmenu from './navmenu'
export default {
    data() {
        return {
            
        }
    },
    components:{
        navmenu
    }
}
</script>
<style scoped>

</style>

<template>
    <div>
        <el-row>
            <el-col>
                
                <el-menu
                    default-active="$route.path"
                    router
                    class="el-menu-vertical-demo"
                    @open="handleOpen"
                    @close="handleClose"
                >
                    <el-submenu index="1">
                        <template slot="title">
                            <i class="el-icon-location"></i>
                            <span>Navigation 1</span>
                        </template>
                        <el-menu-item-group>
                            <template slot="title">Group 1</template>
                            <el-menu-item index="/Elnav/one">Option 1</el-menu-item>
                            <el-menu-item index="/Elnav/two">Option 2</el-menu-item>
                        </el-menu-item-group>
                        <el-menu-item-group title="Group 2">
                            <el-menu-item index="1-3">Option 3</el-menu-item>
                        </el-menu-item-group>
                        <el-submenu index="1-4">
                            <template slot="title">Option 4</template>
                            <el-menu-item index="1-4-1">Option 1</el-menu-item>
                        </el-submenu>
                    </el-submenu>
                </el-menu>
            </el-col>
        </el-row>
    </div>
</template>
<script>
export default {
  methods: {
    handleOpen(key, keyPath) {
      console.log(key, keyPath);
    },
    handleClose(key, keyPath) {
      console.log(key, keyPath);
    }
  },
  mounted() {
    console.log(this.$route);
  }
};
</script>
<style>
</style>

{
    path: "/Elnav",
    name: "Elnav",   
    component: () =>
      import("../components/Elnav.vue"),
      children:[
        {
          path: "/Elnav/one",
          name: "one",   
          component: () =>
            import("../components/one.vue")
        },
        {
          path: "/Elnav/two",
          name: "two",   
          component: () =>
            import("../components/two.vue")
        }
      ]
  }