var routeList = [];
router.beforeEach((to, from, next) => {
 var index = -1;
 for(var i = 0; i < routeList.length; i++) {
  if(routeList[i].name == to.name) {
   index = i;
   break;
  }
 }
 if (index !== -1) {
//如果存在路由列表，則把之后的路由都刪掉
  routeList.splice(index + 1, routeList.length - index - 1);
 } else if(to.name != '登錄'){
  routeList.push({"name":to.name,"path":to.fullPath});
 }
 to.meta.routeList = routeList;
 next()
});

<template>
  <div class="level-bread">
   <el-breadcrumb separator="/">
    <el-breadcrumb-item v-for="item in realList" :to="item.path">{{item.name}}</el-breadcrumb-item>
   </el-breadcrumb>
  </div>
</template>

<script>
  export default {
   name: "lelve-bread",
   created(){
    this.getRoutePath();
   },
   data() {
    return {
     realList: []
    }
   },
   methods:{
    getRoutePath() {
     this.realList = this.$route.meta.routeList;
    }
   },
   beforeRouteEnter(to,from, next) {
    next((vm) => {
     vm.realList = to.meta.routeList;
    });
   },
   // watch:{
   //  $route:function(newV,oldV) {
   //   this.realList =newV.meta.routeList;
   //  }
   // }
  }
</script>

const Foo = {
 template: `...`,
 beforeRouteEnter (to, from, next) {
  // 在渲染該組件的對(duì)應(yīng)路由被 confirm 前調(diào)用
  // 不！能！獲取組件實(shí)例 `this`
  // 因?yàn)楫?dāng)守衛(wèi)執(zhí)行前，組件實(shí)例還沒(méi)被創(chuàng)建
 },
 beforeRouteUpdate (to, from, next) {
  // 在當(dāng)前路由改變，但是該組件被復(fù)用時(shí)調(diào)用
  // 舉例來(lái)說(shuō)，對(duì)于一個(gè)帶有動(dòng)態(tài)參數(shù)的路徑 /foo/:id，在 /foo/1 和 /foo/2 之間跳轉(zhuǎn)的時(shí)候，
  // 由于會(huì)渲染同樣的 Foo 組件，因此組件實(shí)例會(huì)被復(fù)用。而這個(gè)鉤子就會(huì)在這個(gè)情況下被調(diào)用。
  // 可以訪問(wèn)組件實(shí)例 `this`
 },
 beforeRouteLeave (to, from, next) {
  // 導(dǎo)航離開該組件的對(duì)應(yīng)路由時(shí)調(diào)用
  // 可以訪問(wèn)組件實(shí)例 `this`
 }
}