keep-alive

当切换组件要保持数据的及时变换时，用keep-alive

<div

    v-for="(component,index) of components"

    :key="index"

    :class="{active:component.name==currentComponent}"

    @click="currentComponent = component.name"

  >{{component.title}}

  </div>

<keep-alive>

<component :is="currentCopmponent" />

</keep-alive>

export default{

      comments:{Site,Weixin},

      provide(){

        return {webname:computed(()=>this.teacher),config:this.config}

      },

      data(){

        return {

          config,

          teacher:'老师',

          currentComponent:'weixin',

          components:[

            {title:'微信管理',name:'weixin'},

            {title:'网站信息',name:'site'},

          ]

        }

      }

    }