1. 通过按钮控制侧边栏的展开和折叠
2. 通过窗口宽度的变化控制侧边栏的展开和折叠（小于768px,自动折叠）

通过按钮控制展开

通过按钮控制折叠

切换到手机模式自动折叠

环境准备：Vue3+Element-UI Plus

<script setup>
import {onMounted, ref, watch} from "vue";

// 是否折叠菜单
const isCollapse = ref(false)

// 检查窗口宽度，设置侧边栏宽度
function checkClientWidth(){
  console.log(document.body.clientWidth)
  if (document.body.clientWidth < 768) {
    document.querySelector('.el-aside').style.width = 'auto'
    isCollapse.value = true
  } else {
    // el-aside的宽度展开要慢于el-menu
    setTimeout(() => {
      document.querySelector('.el-aside').style.width = '200px'
    }, 300)
    isCollapse.value = false
  }
}

// 监听窗口变化，窗口宽度小于 768px 时，侧边栏会自动收起
window.addEventListener('resize', checkClientWidth)

// 监听点击折叠和展开图片时的变化
watch(isCollapse, (newValue)=>{
  if (newValue) {
    document.querySelector('.el-aside').style.width = 'auto'
  } else {
    // el-aside的宽度展开要慢于el-menu
    setTimeout(() => {
      document.querySelector('.el-aside').style.width = '200px'
    }, 300)
  }
})

onMounted(()=>{
  // 页面刷新时，检查窗口宽度，设置侧边栏宽度
  checkClientWidth()
})

</script>

<template>
  <div class="common-layout">
    <el-container>
      <el-aside>
        <el-menu
            :collapse="isCollapse"
            active-text-color="#ffd04b"
            background-color="#545c64"
            class="el-menu-vertical-demo"
            default-active="2"
            text-color="#fff"
        >
          <el-sub-menu index="1">
            <template #title>
              <el-icon>
                <location/>
              </el-icon>
              <span>Navigator One</span>
            </template>
            <el-menu-item-group title="Group One">
              <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>item four</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>
            <span>Navigator Two</span>
          </el-menu-item>
          <el-menu-item index="3" disabled>
            <el-icon>
              <document/>
            </el-icon>
            <span>Navigator Three</span>
          </el-menu-item>
          <el-menu-item index="4">
            <el-icon>
              <setting/>
            </el-icon>
            <span>Navigator Four</span>
          </el-menu-item>
        </el-menu>
      </el-aside>
      <el-container>
        <el-header>
          <el-row align="middle" style="height: 100%">
            <el-col :span="1">
              <el-icon v-show="isCollapse" @click="isCollapse=false"><Expand /></el-icon>
              <el-icon v-show="!isCollapse" @click="isCollapse=true"><Fold /></el-icon>
            </el-col>
          </el-row>
        </el-header>
        <el-main>Main</el-main>
      </el-container>
    </el-container>
  </div>
</template>

<style scoped lang="scss">
.el-container {
  .el-aside {
    background-color: slategrey;
    height: 100vh;
    width: 200px;
    .el-menu{
      height: 100%;
      width: 100%;
    }
  }

  .el-header {
    background-color: #409EFF;
  }

  .el-main {
    background-color: #E6A23C;
  }
}
</style>