vue 使用localstorage实现面包屑的操作

changeRoute(state, val) {
    let routeList = state.routeList;
    let isFind = false;
    let findeIdex = 0;

    //菜单栏和下拉的二级菜单
    if (val['type'] == 'header' || val['type'] == 'secondHeader')   {
      routeList.length = 0;
      //顶级菜单清除缓存
      localStorage.removeItem("routeList");
    }
    let routes = routeList;
    let localStorageList = localStorage.getItem('routeList');
    if (localStorageList) {
      //当前页刷新,使用缓存数据
      routes = JSON.parse(localStorageList as any);
    }
    //遍历是否有存入当前路由位置
    for (let i = 0; i < routes.length; i++) {
      isFind = routes[i]['name'] == val['name'];
      if (isFind) {
        findeIdex = i;
        break;
      }
    };
    if (isFind) {
      //有的话，清除当前路由以后的数据
      routes.splice(findeIdex + 1, routes.length - findeIdex - 1);
      //修改缓存
      localStorage.setItem('routeList', JSON.stringify(routes));
    } else {
      //存入全局变量
      routes.push(val);
      //设置缓存
      localStorage.setItem('routeList', JSON.stringify(routes));
    }
  }

//获取面包屑缓存
  let localStorageList1 = localStorage.getItem('routeList');
  //ts写法 as any
  this.routeList = JSON.parse(localStorageList1 as any) 
   ? JSON.parse(localStorageList1 as any)
   : { name: 'test', url: '/test' };

<el-menu :unique-opened="true" router :default-active="$route.path" @select="handleSelect">
    <div class="user-menu-box" v-for="menu in menus" :key="menu.id">
      <el-menu-item v-if="!menu.child" :index="menu.path">
        <icon :name="menu.icon" :w="20" :h="20"></icon>
        <span slot="title" v-text="menu.name"></span>
      </el-menu-item>
      <el-submenu v-if="menu.child" :index="menu.path">
        <template slot="title">
          <icon :name="menu.icon" :w="20" :h="20"></icon>
          <span slot="title" v-text="menu.name"></span>
        </template>
        <el-menu-item-group>
          <el-menu-item v-for="subMenu in menu.child" :key="subMenu.id" v-text="subMenu.name"
            :index="subMenu.path"></el-menu-item>
        </el-menu-item-group>
      </el-submenu>
    </div>
</el-menu>

export default {
  data () {
    return {
      activeMenu: '',
      indexBreadcrumbs: [],
      menus: [{
        id: '1',
        name: '门户管理',
        icon: 'menhuguanli',
        path: '#2',
        child: [{
          id: '1-1',
          name: '轮播图',
          path: '/backstage/protaManage/turns'
        }, {
          id: '1-2',
          name: '基础数据',
          path: '/backstage/protaManage/basis'
        }, {
          id: '1-3',
          name: '分类管理',
          path: '/backstage/protaManage/classify'
        }, {
          id: '1-4',
          name: '内容发布',
          path: '/backstage/protaManage/content'
        }]
      }, {
        id: '2',
        name: '我的云盘',
        icon: 'yunpan',
        path: '/backstage/yunManage'
      }, {
        id: '3',
        name: '管理菜单',
        icon: 'shezhi',
        path: '/backstage/menusManage'
      }, {
        id: '4',
        name: '编辑板块',
        icon: 'fabuzhongxin',
        path: '/backstage/editPlate'
      }]
    }
  },
  watch: {
    $route () {
      this.handChange()
    }
  },
  computed: {
    breadcrumbList () {
      let breadcrumbs = []
      let menuList = this.menus
      this.indexBreadcrumbs.map(item => {
        for (let i = 0; i < menuList.length; i++) {
          if (item === menuList[i].path) {
            breadcrumbs.push(menuList[i])
            if (menuList[i].child) {
              menuList = menuList[i].child
            }
            break;
          }
        }
      })
      return breadcrumbs
    }
  },
  methods: {
    handChange () {
      this.$emit('hand-change', this.breadcrumbList)
    },
    handleSelect (index, indexPath) {
      this.indexBreadcrumbs = indexPath
    }
  },
  created () {
    this.handChange()
  }
}

<el-breadcrumb separator-class="el-icon-arrow-right">
   <el-breadcrumb-item :to="{ path: '/backstage' }">首页</el-breadcrumb-item>
   <el-breadcrumb-item v-for="o in breadcrumbList" :key="o.id">{{o.name}}
   </el-breadcrumb-item>
 </el-breadcrumb>