ElementUI

<template>
  <div id="app">
    <el-container>
      <el-header>
        <el-menu :default-active="onRoutes" mode="horizontal" @select="handleSelect" background-color="#545c64"
          text-color="#fff" active-text-color="#ffd04b" :router="true">
          <el-menu-item index="/home">首页</el-menu-item>
          <el-menu-item index="/freeCourse">免费课程</el-menu-item>
        </el-menu>
      </el-header>
      <el-main>
        <router-view />
      </el-main>
    </el-container>
  </div>
</template>

<script>
  export default {
    name: ‘App‘,
    data() {
      return {

      }
    },
    methods: {
      //打印el-menu-item的index，path
      handleSelect(index, path) {
        console.log(index, path);
      }
    },
    computed: {
      onRoutes() {
        //刷新后保存默认激活样式
        let path = this.$route.path;
        return path;
      }
    }
  }
</script>

<style>
</style>