vue路由中前进后退的一些事儿

<keep-alive>
//这是会被缓存的页面
 <router-view v-if="$route.meta.keepAlive">
 </router-view></keep-alive>
<router-view v-if = "!$route.meta.keepAlive">
//这里是不被缓存的组件
</router-view>

routes:[
 {  path: '/', 
   name: 'Index', 
   component: Index,  
   meta:{ 
    title:"博物馆",  
    keepAlive:false//不缓存 
   } 
   }, 
   { 
   path:'/searchMain', 
   name:'SearchMain', 
   component:SearchMain, 
   meta:{ 
    title:"搜索", 
    keepAlive:true,//缓存 
     } 
   },
   { 
   path:'/collectionDetails', 
   name:'CollectionDetails', 
   component:CollectionDetails, 
   meta:{  
    title:"藏品详情", 
    keepAlive:false,//不缓存 
    } 
   }]

beforeRouteLeave(to, from, next) { 
  if(to.path="首页"){
   from.meta.keepAlive =false;
  }else if(to.path="详情页"){
  from.meta.keepAlive = true;
  } // 跳转到 首页时，不缓存，跳转到详情页时缓存（就是不刷新） 
  next();
  }
这种行吗？行吗？行吗？不行！！因为第一次的时候确实会成功，可是退出去以后就gg了，
因为keepAlive已经变成了false,第二次就不会缓存。那么第一个页面加下面代码，让他进入的时候
 beforeRouteLeave(to, from, next) { 
  if(to.path=="/searchMain"){ 
  to.meta.keepAlive =true;  
  } 
  next(true); 
 return; 
},

beforeRouteEnter ->created ->mounted ...->activated ->deactivated

beforeRouteEnter ->activated ->deactivated

 activated() {
 if(!this.$route.meta.isBack) {
  // 如果isBack是false，表明需要获取新数据，否则就不再请求，直接使用缓存的数据  this.getData(); // ajax获取数据方法
 }
 // 恢复成默认的false，避免isBack一直是true，导致下次无法获取数据
 this.$route.meta.isBack = false
},

<keep-alive>
   <router-view v-if="$route.meta.keepAlive" :key='key'></router-view>
</keep-alive>
   <router-view v-if="!$route.meta.keepAlive" :key='key'></router-view>

beforeRouteLeave(to,from,next){
 if(to.path=="/"){
  this.$store.commit("UPDATE_KEY",this.$route.name!==undefined?this.$route.name+
  +new Date():this.$route+ +new Date());
 }
}

beforeRouteLeave(to,from,next){
 if(to.path=="/"){
  this.$store.commit("UPDATE_KEY",this.$route.name!==undefined?this.$route.name+ +new Date():this.$route+ +new Date());
     this.$destroy();//销毁吧
}