如何在Vue项目中使用路由实现页面刷新和缓存控制？

import VueRouter from 'vue-router'
import Vue from 'vue'

Vue.use(VueRouter)

const routes = [
  {
    path: '/',
    name: 'Home',
    component: () => import('@/views/Home.vue')
  },
  {
    path: '/about',
    name: 'About',
    component: () => import('@/views/About.vue')
  },
  // ...
]

const router = new VueRouter({
  mode: 'history',
  base: process.env.BASE_URL,
  routes
})

export default router

// 在App.vue中添加如下代码
beforeMount() {
  // 判断是否是刷新操作
  if (!performance.navigation.type) {
    // 获取之前保存的状态
    const state = sessionStorage.getItem('state')
    if (state) {
      // 恢复之前的状态
      this.$store.replaceState(JSON.parse(state))
    } else {
      // 第一次访问，保存当前状态
      sessionStorage.setItem('state', JSON.stringify(this.$store.state))
    }
  }
},
beforeDestroy() {
  // 刷新前保存当前的状态
  sessionStorage.setItem('state', JSON.stringify(this.$store.state))
}

<template>
  <div>
    <keep-alive>
      <router-view v-if="$route.meta.cache" />
    </keep-alive>
    <router-view v-if="!$route.meta.cache" />
  </div>
</template>

<script>
export default {
  name: 'App',
  beforeRouteUpdate(to, from, next) {
    // 判断是否需要缓存页面
    if (to.meta.cache) {
      // 设置页面的缓存状态
      this.$children.forEach(child => {
        if (child.$vnode && child.$vnode.data.keepAlive) {
          child.$vnode.parent.componentInstance.cache[child.$vnode.key] = child;
        }
      })
      next()
    } else {
      // 清除之前缓存的页面状态
      this.$children.forEach(child => {
        if (child.$vnode && child.$vnode.data.keepAlive) {
          if (child.$vnode.parent.componentInstance.cache[child.$vnode.key]) {
            delete child.$vnode.parent.componentInstance.cache[child.$vnode.key];
          }
        }
      })
      next()
    }
  }
}
</script>