vue緩存之keep-alive，設置想要緩存的頁面

結合router，緩存部分頁面
<keep-alive>
    <router-view v-if="$route.meta.keepAlive"></router-view>
</keep-alive>
<router-view v-if="!$route.meta.keepAlive"></router-view>
{
  path: '/',
  name: 'Hello',
  component: Hello,
  meta: {
    keepAlive: false // 不需要緩存
  }
},