代码

<transition name="router-fade" mode="out-in">
  <keep-alive>
    <router-view v-if="$route.meta.keepAlive"></router-view>
  </keep-alive>
</transition>
<transition name="router-fade" mode="out-in">
  <router-view v-if="!$route.meta.keepAlive"></router-view>
</transition>

提示信息

[Vue Router warn]: <router-view> can no longer be used directly inside <transition> or <keep-alive>.
Use slot props instead:

<router-view v-slot="{ Component }">
  <transition>
    <component :is="Component" />
  </transition>
</router-view>

修正

        <router-view v-slot="{ Component }">
            <transition name="router-fade" mode="out-in">
                <keep-alive>
                    <component :is="Component"/>
                </keep-alive>
            </transition>
        </router-view>