<div>
      <ul class="nav nav-tabs">
        <li>
          <router-link class="list-group-item" active-class="active" to="/home/news">News</router-link>
        </li>
        <li>
          <router-link class="list-group-item" active-class="active" to="/home/message">Message</router-link>
        </li>
      </ul>
      <keep-alive include="News">
        <router-view></router-view>
      </keep-alive>
    </div>

<template>
  <ul>
    <li :style="{opacity}">歡迎學習Vue</li>
    <li>news001 <input type="text"></li>
    <li>news003 <input type="text"></li>
  </ul>
</template>


<script>
  export default {
    name:'News',
    data() {
      return {
        opacity:1
      }
    },
    activated() {
      console.log('News組件被激活了')
      this.timer = setInterval(() => {
        console.log('@')
        this.opacity -= 0.01
        if(this.opacity <= 0) this.opacity = 1
      },16)
    },
    deactivated() {
      console.log('News組件失活了')
      clearInterval(this.timer)
    },
  }
</script>