<!-- 父组件中 -->
<el-menu
	class="h-full"
	background-color="#fff"
	:default-active="formData.materialCategory"
  @select="selectCategory"
 >
    <DropdownItem v-for="item in menuTree" :key="item.id" :item="item" />
</el-menu>

<!-- DropdownItem.vue 子组件 -->
<template>
  <el-sub-menu v-if="item?.children?.length" :index="item.id + ''">
    <template #title>
      <span>{{ item.label }}</span>
    </template>
	<!-- DropdownItem应该和vue文件名保持一致，具体参阅官方文档 -->
    <DropdownItem v-for="child in item.children" :key="child.id" :item="child" />
  </el-sub-menu>
  <el-menu-item v-else :index="item.id + ''">
    {{ item.label }}
  </el-menu-item>
</template>
<script setup>
defineProps({
  item: {
    type: Object,
    default: () => ({})
  }
});
</script>