详解Vue3子组件向父组件传递消息

<!-- 子组件A -->
<template>
  <div style="color:coral">
    我是B的子组件A
  </div>
</template>
<script setup>
	import { onMounted } from "vue";
	const props = defineProps({
	  msg: String
	})
	onMounted(() => {
	  console.log('我是A，我接收到B给我传递的消息', props);
	})
</script>

<!-- 父组件B -->
<template>
  <div>
    <h1>我是父组件B，下面是我的子组件A</h1>
    <A msg="我是父组件B，我现在向A组件传递消息"></A>
  </div>
</template>
<script setup>
	import A from "../components/A.vue"
</script>

<!-- 子组件A -->
<template>
  <div style="background:gainsboro">
    <h3 style="color:coral">我是B的子组件A</h3>
    <button @click="send">向B发消息</button>
  </div>
</template>
<script setup>
	import { onMounted } from "vue";
	const props = defineProps({
	  msg: String,
	  myFn: Function
	})
	onMounted(() => {
	  console.log('我是红薯我是红薯，收到收到', props);
	})
	const send = () => {
	  props.myFn('我是A,我调用B的事件向它发送此消息：嘿~土豆')
	}
</script>

<!-- 父组件B -->
<template>
  <div>
    <p>我是父组件B，我传递给A组价的事件，A调用后我可以接收到：
      <span style="color:darkorange">{{state.childMsg}}</span>
    </p>
    <h1>我是父组件B，下面是我的子组件A</h1>
    <A
      msg="我是土豆我是土豆，收到请回答"
      :myFn="state.fn"
    ></A>
  </div>
</template>
<script setup>
	import { reactive } from "vue";
	import A from "../components/A.vue"
	const state = reactive({
	  childMsg: '暂无消息',
	  fn: (data) => {
	    state.childMsg = data
	  }
	})
</script>