el-menu使用递归组件实现多级菜单组件

1. 效果：

2. 实现：

创建外层菜单AsideMenu.vue组件和子菜单项AsideSubMenu.vue组件，在AsideSubMenu中进行递归操作。

AsideMenu.vue文件内容如下：

<template>
  <aside class="wrap">
    <el-menu
      :default-active="activeMenu"
      router
      :class="'menu-left'"
      :default-openeds="openedsArr"
      text-color="#fff"
    >
      <AsideSubMenu :menuData="menuData"></AsideSubMenu>
    </el-menu>
  </aside>
</template>

<script>
import AsideSubMenu from "./AsideSubMenu.vue";
export default {
  name: "AsideMenu",
  components: {
    AsideSubMenu,
  },
  props: {
    menuData: {
      type: Array,
    },
  },
  computed: {
    activeMenu() {
      const route = this.$route;
      const { meta, path } = route;
      // 此处添加判断的原因见说明
      if (meta.matchPath) {
        return meta.matchPath;
      } else {
        return path;
      }
    },
    // 设置默认展开菜单项
    openedsArr() {
      // const arr = this.menuData.map((item) => {
      //   return item.title;
      // });
      // return arr;
      return [];
    },
  },
};
</script>

判断高亮状态的activeMenu方法中的判断matchPath属性可以让多个路由不同的页面匹配同一个菜单高亮状态，因为菜单高亮状态是根据路由地址匹配的。如果两个不同的路由页面想公用同一个菜单高亮状态（如详情页面和列表页）就可以使用该方法实现。在router文件里设置meta对象，添加matchPath属性设置为想要共用的高亮状态的页面的路由地址。（有点绕??）

样式根据需求修改，示例中的样式如下（此处包含深浅两种主题的菜单样式）：

点击查看代码

<style scoped>
aside {
  height: 100%;
  text-align: center;
}
.el-menu {
  padding: 16px;
  box-sizing: border-box;
}
/* ---------- 深色 ---------- */
.menu-left,
.menu-left /deep/ .el-menu {
  min-height: 100%;
  background-color: #222653;
}
.menu-left .icon {
  width: 20px;
  margin-right: 9px;
}
.menu-left /deep/.el-submenu__title,
.menu-left /deep/.el-menu-item {
  box-sizing: border-box;
  font-size: 14px;
  font-family: PingFangSC-Regular, PingFang SC;
  text-align: left;
  color: #b3c0e7 !important;
  background-color: #222653 !important;
}
.menu-left /deep/.el-submenu__title i {
  color: #b3c0e7 !important;
}
.menu-left /deep/.el-submenu__title {
  height: 54px;
  line-height: 54px;
  /* padding-left: 36px !important; */
}
.menu-left /deep/ .el-menu-item {
  height: 52px;
  line-height: 52px;
}
.menu-left /deep/.el-submenu .el-menu-item {
  padding-left: 45px !important;
}
/* 外层高亮 */
.menu-left /deep/.el-submenu.is-active,
.menu-left /deep/.el-submenu.is-active .el-menu-item,
.menu-left /deep/.el-submenu.is-active .el-submenu__title,
.menu-left /deep/.el-menu-item.is-active {
  background-color: #4880ff !important;
}
.menu-left /deep/.el-submenu.is-active {
  border-radius: 10px;
  overflow: hidden;
}
.menu-left /deep/ .el-menu-item.is-active {
  border-radius: 10px;
}
.menu-left /deep/ .el-menu--inline .el-menu-item.is-active,
.menu-left /deep/ .el-submenu.noIcon {
  border-radius: 0;
}
.menu-left /deep/ .el-submenu.noIcon .el-submenu__title {
  padding-left: 45px !important;
}
.menu-left /deep/ .el-submenu.noIcon .el-menu-item {
  padding-left: 58px !important;
}
.menu-left /deep/.el-submenu.is-active > .el-submenu__title,
.menu-left /deep/.el-submenu.is-active > .el-submenu__title i {
  color: #ffffff !important;
}
/* 内层高亮 */
.menu-left /deep/.el-menu-item:focus,
.menu-left /deep/.el-menu-item:hover,
.menu-left /deep/.el-menu-item.is-active {
  color: #ffffff !important;
  font-weight: 500;
}
.menu-left /deep/.el-menu-item.is-disabled {
  padding-left: 45px !important;
  color: #ffffff !important;
}

/* ---------- 浅色 ---------- */
.menu-left-light {
  height: 100%;
  background-color: #f8f8f8;
}
.menu-left-light .icon {
  width: 20px;
  margin-right: 9px;
}
.menu-left-light /deep/.el-submenu__title,
.menu-left-light /deep/.el-menu-item {
  box-sizing: border-box;
  font-size: 16px;
  font-family: PingFangSC-Regular, PingFang SC;
  text-align: left;
  color: #333333;
}
.menu-left-light /deep/.el-submenu__title {
  height: 52px;
  line-height: 52px;
  padding-left: 56px !important;
}
.menu-left-light /deep/.el-submenu__title:hover {
  background-color: #ffffff !important;
}
.menu-left-light /deep/.el-submenu__icon-arrow {
  right: 85px;
}
.menu-left-light /deep/.el-submenu__title i {
  color: #333333;
}
.menu-left-light /deep/.el-menu-item {
  height: 40px;
  line-height: 40px;
  padding-left: 82px !important;
  border-left: 4px solid #ffffff;
}
.menu-left-light /deep/.el-menu-item:focus,
.menu-left-light /deep/.el-menu-item:hover,
.menu-left-light /deep/.el-menu-item.is-active {
  background: rgba(31, 65, 219, 0.1) !important;
  color: #1f41db !important;
  border-color: #1f41db;
}
.menu-left-light /deep/.el-menu-item.is-disabled {
  background: #ffffff !important;
  color: #333333 !important;
}
</style>

AsideMenu.vue文件内容如下：

<template>
  <div>
    <template v-for="item in menuData">
      <el-submenu
        :key="item.path"
        v-if="item.children && item.children.length > 0"
        :index="item.path"
        :class="item.icon ? '' : 'noIcon'"
      >
        <template slot="title">
          <img
            class="icon mr-r-10"
            :src="
              curRoute.indexOf(item.path) != -1 ? item.iconActive : item.icon
            "
          />
          <span>{{ item.title }}</span>
        </template>
        <AsideSubMenu :menuData="item.children"></AsideSubMenu>
      </el-submenu>
      <el-menu-item
        :key="item.id"
        v-else
        :index="item.path"
        :disabled="item.disabled"
      >
        <template slot="title">
          <img
            class="icon mr-r-10"
            :src="
              curRoute.indexOf(item.path) != -1 ? item.iconActive : item.icon
            "
          />
          <span>{{ item.title }}</span>
        </template>
      </el-menu-item>
    </template>
  </div>
</template>

判断如果有子菜单则进行遍历操作。同时此处根据是否有icon给el-submenu动态添加了一个类名:class="item.icon ? '' : 'noIcon'"，这么做是由于高亮状态下的.el-submenu添加了圆角效果，在存在多层子菜单嵌套的情况下如果不清除圆角效果则会出现问题（见下图）。这个状态下不好用选择器选中需要操作的元素，因此根据是否有icon这个区别进行了区分。如果是整个菜单都没有icon的情况的话，那暂时还没想好应对策略。??

<script>
import AsideSubMenu from "./AsideSubMenu.vue";
export default {
  name: "AsideSubMenu",
  components: {
    AsideSubMenu,
  },
  props: {
    menuData: {
      type: Array,
      default: () => {
        return [];
      },
    },
  },
  computed: {
    curRoute() {
      return this.$route.path;
    },
  },
};
</script>

3. 使用组件：

• 添加路由配置；
• 引入并挂载组件；
• 传入菜单数据；

代码如下：

<template>
  <el-container class="container">
    <el-aside width="320px">
      <AsideMenu :menuData="menuData"></AsideMenu>
    </el-aside>
    <el-main>
      <keep-alive :exclude="[]">
        <router-view></router-view>
      </keep-alive>
    </el-main>
  </el-container>
</template>

<script>
import AsideMenu from '@/components/AsideMenu.vue';
export default {
  name: 'MenuTest',
  components: {
    AsideMenu
  },
  data() {
    return {
      menuData: [
        {
          title: '菜单一',
          path: '/menutest/menu1',
          icon: require('@/assets/icons/apply.svg'),
          iconActive: require('@/assets/icons/apply_active.svg'),
          children: [
            {
              title: '子菜单一',
              path: '/menutest/menu1/menu1-1',
              // disabled: true,
            },
            {
              title: '子菜单二',
              path: '/menutest/menu1/menu1-2'
            }
          ]
        },
        {
          title: '菜单二',
          path: '/menutest/menu2',
          icon: require('@/assets/icons/apply.svg'),
          iconActive: require('@/assets/icons/apply_active.svg'),
          children: [
            {
              title: '子菜单一',
              path: '/menutest/menu2/menu2-1'
            },
            {
              title: '子菜单二',
              path: '/menutest/menu2/menu2-2',
              children: [
                {
                  title: '孙子菜单一',
                  path: '/menutest/menu2/menu2-2/menu2-1-1'
                },
                {
                  title: '孙子菜单二',
                  path: '/menutest/menu2/menu2-2/menu2-2-2'
                }
              ]
            },
            {
              title: '子菜单三',
              path: '/menutest/menu2/menu2-3'
            }
          ]
        },
        {
          title: '菜单三',
          path: '/menutest/menu3',
          icon: require('@/assets/icons/apply.svg'),
          iconActive: require('@/assets/icons/apply_active.svg'),
        }
      ]
    };
  }
};
</script>

<style scoped>
.container {
  min-height: 800px;
}
.el-main {
  padding: 32px 40px;
  box-sizing: border-box;
  background: #f5f5fa;
  overflow-y: auto;
}
</style>

示例中的路由配置如下：

  {
    path: "/menutest",
    name: "Menu",
    component: () => import("../views/MenuTest.vue"),
    redirect: "/menutest/menu1",
    children: [{
        path: '/menutest/menu1',
        component: () => import("../views/menuPages/menu1.vue"),
        children: [{
            path: '/menutest/menu1/menu1-1',
            component: () => import("../views/menuPages/menu1-1.vue"),
          },
          {
            path: '/menutest/menu1/menu1-2',
            component: () => import("../views/menuPages/menu1-2.vue"),
          }
        ]
      },
      {
        path: '/menutest/menu2',
        component: () => import("../views/menuPages/menu2.vue"),
        children: [{
            path: '/menutest/menu2/menu2-1',
            component: () => import("../views/menuPages/menu2-1.vue"),
          },
          {
            path: '/menutest/menu2/menu2-2',
            component: () => import("../views/menuPages/menu2-2.vue"),
            children: [{
                path: '/menutest/menu2/menu2-2/menu2-1-1',
                component: () => import("../views/menuPages/menu2-1-1.vue"),
              },
              {
                path: '/menutest/menu2/menu2-2/menu2-2-2',
                component: () => import("../views/menuPages/menu2-1-2.vue"),
              }
            ]
          },
          {
            path: '/menutest/menu2/menu2-3',
            component: () => import("../views/menuPages/menu2-3.vue"),
          }
        ]
      },
      {
        path: '/menutest/menu3',
        component: () => import("../views/menuPages/menu3.vue"),
      }
    ]
  }