一、原理

根据v-for遍历菜单参数，渲染导航栏。

使用Element UI 的 Container 布局容器和NavMenu导航菜单组件，使用router-view存放二级路由出口。

二、效果

三、实现案例

html：

  <el-container>
    <el-aside
      class="aside flex-shrink-0"
      style="width:260px;height: 100%;"
    >
    
    <el-menu
      class="border-r-0"
      style="height: 100%;"
      router
      :default-active="menuActive"
      @select="menuChange"
    >
      <template v-for="(item,index) in menuList">
        <el-submenu
          :key="item.dictValue"
          :index="item.dictValue"
        >
          <template slot="title">
            <i class="el-icon-document" />
            <span>{{ item.dictLabel }}</span>
          </template>
          <el-menu-item
            v-for="child in item.children"
            :key="`${child.dictValue}`"
            :index="`${child.dictValue}`"
            :route="{ name: child.dictValue }"
          >
            <i class="el-icon-document" />
            <span slot="title">{{ child.dictLabel }}</span>
          </el-menu-item>
        </el-submenu>
      </template>
    </el-menu>
    </el-aside>
    < !-- 二级路由出口 -->
    <router-view />
  </el-container>

js：

export default {
  name: 'test',
  components: {
  },
  data() {
    const menuList = [
      {
        dictLabel: '导航一',
        dictValue: '1',
        children: [
          { dictLabel: '分组一', dictValue: 'group1Item1'},
        ],
      },
      {
        dictLabel: '导航二',
        dictValue: '2',
        children: [
          { dictLabel: '分组一', dictValue: 'group2Item1'},
        ],
      },
    ]
    return {
      menuList,
      menuActive: menuList[0].children[0]?.dictValue,
    };
  },
  watch: {
    '$route.path': function watch() {
      const { name, params } = this.$route;
      this.menuActive = `${name}${params.type || ''}`;
    },
  },
  mounted() {
    // 刷新页面时默认展示当前路由
    const { name, params } = this.$route;
    this.menuActive =  `${name}${params.type || ''}`;
  },
  methods: {
    menuChange(index) {
      this.menuActive = index;
    },
  },
};

router/index.js: 

配置路由

      {
        path: 'test',
        name: 'test',
        meta: {
          title: '菜单',
        },
        redirect: '/test/group1Item1', // 默认页面
        component: () => import('@/test/index.vue'),
        children: [
          {
            path: 'group1Item1',
            name: 'group1Item1',
            meta: {
              title: '导航一分组一',
            },
            component: () => import('@/test/group1Item1.vue'),
          },
          {
            path: 'group2Item1',
            name: 'group2Item1',
            meta: {
              title: '导航二分组一',
            },
            component: () => import('@/test/group2Item1.vue'),
          }
        ]
      },