el-menu 折叠后小箭头不会消失

官方示例

<template>
  <el-radio-group v-model="isCollapse" style="margin-bottom: 20px">
    <el-radio-button :value="false">expand</el-radio-button>
    <el-radio-button :value="true">collapse</el-radio-button>
  </el-radio-group>
  <el-menu
    default-active="2"
    class="el-menu-vertical-demo"
    :collapse="isCollapse"
    @open="handleOpen"
    @close="handleClose"
  >
    <el-sub-menu index="1">
      <template #title>
        <el-icon><location /></el-icon>
        <span>Navigator One</span>
      </template>
      <el-menu-item-group>
        <template #title><span>Group One</span></template>
        <el-menu-item index="1-1">item one</el-menu-item>
        <el-menu-item index="1-2">item two</el-menu-item>
      </el-menu-item-group>
      <el-menu-item-group title="Group Two">
        <el-menu-item index="1-3">item three</el-menu-item>
      </el-menu-item-group>
      <el-sub-menu index="1-4">
        <template #title><span>item four</span></template>
        <el-menu-item index="1-4-1">item one</el-menu-item>
      </el-sub-menu>
    </el-sub-menu>
    <el-menu-item index="2">
      <el-icon><icon-menu /></el-icon>
      <template #title>Navigator Two</template>
    </el-menu-item>
    <el-menu-item index="3" disabled>
      <el-icon><document /></el-icon>
      <template #title>Navigator Three</template>
    </el-menu-item>
    <el-menu-item index="4">
      <el-icon><setting /></el-icon>
      <template #title>Navigator Four</template>
    </el-menu-item>
  </el-menu>
</template>

我的代码

<el-menu
    router
    :default-active="route.path"
    class="sidebar-menu"
    :collapse="isCollapse"
    :unique-opened="true"
  >
    <div v-for="item in menuList" :key="item.name">
      <el-sub-menu v-if="item.children && item.children.length > 0" :index="item.path">
        <template #title>
          <el-icon class="menu-icon" v-if="item.meta && item.meta.icon">
            <component :is="item.meta.icon" />
          </el-icon>
          <!--默认图标-->
          <el-icon class="menu-icon" v-else>
            <component :is="Operation" />
          </el-icon>
          <span>{{ item.name }}</span>
        </template>

代码逻辑中遍历menuList动态添加菜单，问题就出在这里，div破坏了原有的菜单结构，会出现奇怪的问题

总结

• 使用template替换原来的div标签，<template v-for="item in menuList" :key="item.name">
• 必须保持原有的菜单结构完整性，el-menu直接包含el-sub-menu或者el-menu-item
• 网上大多数办法是通过修改css样式才生效，实际上都是破坏了原有的结构后的不必要操作