vue实现侧边导航栏

<div class="sidebar">
    <el-menu
      class="sidebar-el-menu"
      :default-active="onRoutes"
      :collapse="collapse"
      background-color="#324157"
      text-color="#bfcbd9"
      active-text-color="#20a0ff"
      unique-opened
      router
    >
      <template v-for="item in items" :v-if="item.isShow===1">
        <template v-if="item.subs">
          <el-submenu :index="item.index" :key="item.index">
            <template slot="title">
              <i :class="item.icon"></i>
              <!-- <i class="iconfont icon-renwu"></i> -->
              <span slot="title">{{ item.title }}</span>
            </template>
            <template v-for="subItem in item.subs">
              <!--<el-submenu v-if="subItem.subs" :index="subItem.index" :key="subItem.index">-->
              <!--<template slot="title">{{ subItem.title }}</template>-->
              <!--<el-menu-item v-for="(threeItem,i) in subItem.subs" :key="i" :index="threeItem.index">-->
              <!--{{ threeItem.title }}-->
              <!--</el-menu-item>-->
              <!--</el-submenu>-->
              <el-menu-item
                v-if="subItem.isShow===1"
                :index="subItem.index"
                :key="subItem.index"
              ><i class="iconfont icon-admin_dian"></i>{{ subItem.title }}</el-menu-item>
            </template>
          </el-submenu>
        </template>
        <template v-else>
          <el-menu-item :index="item.index" :key="item.index">
            <i :class="item.icon"></i>
            <span slot="title">{{ item.title }}</span>
          </el-menu-item>
        </template>
      </template>
    </el-menu>
  </div>

JavaScript代码

beforeCreate: function() {
    //这里出现了生命周期钩子函数，如果是created就无效
    //对于created和mounted的区别，总结就是created的dom还没被vue的dom替换,其他都是一样的
    let self = this;
    let leftMenu = [ ];
    this.postRequest("admin/leftMenu", {
      token: ""
    }).then(function(response) {
      for (let num of response.data.data) {
        let menuItem = {};
        menuItem.subs = [];
        menuItem.index = num.menuName;
        menuItem.title = num.menuNameCn;
        menuItem.icon = `iconfont icon-${num.menuName}`;
        menuItem.isShow = num.isShow;
        if (num.childMenu !== null) {
          for (let subNum of num.childMenu) {
            let subMenu = {};
            subMenu.index = subNum.menuName;
            subMenu.isShow = subNum.isShow;
            subMenu.title = subNum.menuNameCn; //关于对象数组的遍历获取，肯定有更便捷的方法……
            menuItem.subs.push(subMenu); //这里是转换数据格式而不是遍历判断，模板中判断了一次有没有二三级菜单，JS中也需要，来转换数据格式
          }
        }
        leftMenu.push(menuItem);
      }
      self.items = leftMenu.concat(self.items);
    });
  },
  data() {
    return {
      collapse: false,
      // items:[]
      items: [],
    };
  },
  computed: {
    onRoutes() {
      return this.$route.path.replace("/", "");
    }
  },
  created() {
    // 通过 Event Bus 进行组件间通信，来折叠侧边栏
    bus.$on("collapse", msg => {
      this.collapse = msg;
    });
  }
};

可以同过event bus进行侧边栏的折叠效果