<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
  </head>

  <body>
    <div id="app">
      <comp ref='furong'> </comp>
      <button type="button" @click="refs">获取子</button>
    </div>

    <template id="comp">
      <div id="">
        <p>{{message}}</p>
      </div>
    </template>

    <script>
      // 子组件
      const comp = Vue.extend({
        template: '#comp',
        data() {
          return {
            message: 'Hello Vue.js!',
            books: [{
                name: 'HTML/HTML5基础',
                price: 15.5,
              },
              {
                name: '高健壮性CSS',
                price: 16.5,
              },
              {
                name: '深入学习JS',
                price: 17.5,
              },
            ]
          }
        },
      })

      // root
      const app = new Vue({
        el: '#app',
        components: {
          comp,
        },
        methods: {
          refs() {
            // 不常用$children
            console.log(this.$children);
            // 常用$refs 对象类型（默认空对象）
            console.log(this.$refs.furong.message);
          }
        }
      })
    </script>
  </body>
</html>


vue父子访问refs_$refs