从嵌套子组件内部访问父组件，而不在父组件中呈现子组件的HTML

<template>
  <div>
    <child-component :message="message"></child-component>
  </div>
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  components: {
    ChildComponent
  },
  data() {
    return {
      message: 'Hello from parent component!'
    };
  }
};
</script>

<template>
  <div>
    <p>{{ message }}</p>
    <button @click="sendMessageToParent">Send Message to Parent</button>
  </div>
</template>

<script>
export default {
  props: ['message'],
  methods: {
    sendMessageToParent() {
      // 在子组件中触发一个自定义事件，将消息发送给父组件
      this.$emit('message-to-parent', 'Hello from child component!');
    }
  }
};
</script>

<template>
  <div>
    <child-component :message="message" @message-to-parent="handleMessageFromChild"></child-component>
  </div>
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  components: {
    ChildComponent
  },
  data() {
    return {
      message: 'Hello from parent component!'
    };
  },
  methods: {
    handleMessageFromChild(message) {
      console.log('Message from child component:', message);
    }
  }
};
</script>