---

前言

之前简单的封装了一下菜单组件，数据都是写死的，多层嵌套没有支持，学完了组件传值，计算属性就可以继续完善了。

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多层菜单封装

先看下数据结构：

 {
        "id":"1",
        "name":"系统管理",
        "path":"/system",
        "hidden":false,
        "icon":"mdi:mdi-minus",
        "component":"",
        "redirect":"noDirect",
        "children": [
          {        
            "id":"11",
            "name":"用户管理",
            "path":"/user",
            "hidden":false,
            "icon":"mdi:mdi-account",
            "component":"",
            "redirect":"noDirect",
            "children":[
              {        
              "id":"111",
              "name":"小白兔",
              "path":"/user",
              "hidden":false,
              "icon":"mdi-account",
              "component":"",
              "redirect":"noDirect",
              "children":[] 
              }
            ] 
          }
        ]
      }

数据有多层，所以使用嵌套，定义一个item组件NavigationItem.vue：

<template>

      <div v-if=hasChildren>
        <v-list-group :value="navigationItem.name">
          <template v-slot:activator="{ props }">
            <v-list-item
              v-bind="props"
              :title="navigationItem.name"
              prepend-icon="mdi:mdi-minus"
            ></v-list-item>
          </template>

          

          <NavigationItem v-for="child in navigationItem.children"
          :key = child.id
          :navigationItem = child
          >
          </NavigationItem>
        </v-list-group>
      </div>
      <div v-else >
          <v-list-item :prepend-icon="navigationItem.icon" :title="navigationItem.name" :value="navigationItem.name"></v-list-item> 
        </div>
       
</template>
    <script  lang='ts' setup name="Navigation">
    import { computed, onMounted, ref } from 'vue';
    import {NavigationItemInterface} from '@/types'
    

    const {navigationItem} = defineProps<{navigationItem:NavigationItemInterface}>()

    //组合式计算属性写法
    let hasChildren = computed(()=>{
      return navigationItem.children.length>0
    })

    
</script>

重点思路：如果有子节点就展示v-list-group，然后调用自己，如果没有子节点就展示v-list-item。

父组件还用之前的Navigation.vue，修改成调用子组件并传值：

<template>

        <v-navigation-drawer
          v-model="drawer"
          :rail="rail"
          permanent
          @click="rail = false"
        >
          <v-list-item
            prepend-avatar="https://randomuser.me/api/portraits/men/88.jpg"
            title="John Leider"
            nav
          >
            <template v-slot:append>
              <v-btn
                variant="text"
                icon="mdi:mdi-chevron-left"
                @click.stop="rail = !rail"
              ></v-btn>
            </template>
          </v-list-item>
          <v-divider></v-divider>
          
          <!-- 菜单---start -->
          <v-list density="compact" nav>

              <NavigationItem  
                v-for="navigationItem in navigationItems"
                :navigationItem = "navigationItem"
                :key = navigationItem.id
              ></NavigationItem>
          </v-list>
          <!-- 菜单---end -->
        </v-navigation-drawer>
        

  </template>
  <script  lang='ts' setup name="Navigation">
    import { ref } from 'vue';


    let drawer=ref(true)
    let rail=ref(false)//false代表展开
    let navigationItems = ref([
      {
        "id":"1",
        "name":"系统管理",
        "path":"/system",
        "hidden":false,
        "icon":"mdi:mdi-minus",
        "component":"",
        "redirect":"noDirect",
        "children": [
          {        
            "id":"11",
            "name":"用户管理",
            "path":"/user",
            "hidden":false,
            "icon":"mdi:mdi-account",
            "component":"",
            "redirect":"noDirect",
            "children":[
              {        
              "id":"111",
              "name":"小白兔",
              "path":"/user",
              "hidden":false,
              "icon":"mdi-account",
              "component":"",
              "redirect":"noDirect",
              "children":[] 
              }
            ] 
          }
        ]
      },
      {
        "id":"2",
        "name":"开发工具",
        "path":"/system",
        "hidden":false,
        "icon":"mdi:mdi-tools",
        "component":"",
        "redirect":"noDirect",
        "children":[] 
      },
      {
        "id":"3",
        "name":"UI元素",
        "path":"/contact",
        "hidden":false,
        "icon":"mdi:mdi-ubisoft",
        "component":"",
        "redirect":"noDirect",
        "children":[] 
      },
      {
        "id":"4",
        "name":"联系我们",
        "path":"/contact",
        "hidden":false,
        "icon":"mdi:mdi-contacts",
        "component":"",
        "redirect":"noDirect",
        "children":[] 
      },

    ])
</script>

子组件接口定义：

export interface NavigationItemInterface{
    children: Array<NavigationItemInterface>,
      id:string,
      name:string,
      hidden:boolean,
      icon:string,
      component:string,
      redirect:string,
      path:string

  }

效果展示：

总结

在前文的基础上对左侧导航栏组件完善了一下。

心向阳光，阴影自退。