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console 命令行工具 X clear

                    
>
console
Vue.component('component-a', {
  template: '<div>子组件</div>',
  data: function() {
    return {
      message: '子组件内容'
    }
  }
});

var app = new Vue({
  el: '#app',
  methods: {
    handleRef: function() {
      var msg = this.$refs.comA.message;
      console.log(msg);
    }
  }
})
<div id="app">
  <button @click="handleRef">通过ref获取子组件实例</button>
  <component-a ref="comA"></component-a>
</div>
<script src="https://cdn.bootcss.com/vue/2.4.4/vue.js"></script>