vue3 setup语法糖之组件传参(defineProps、defineEmits、defineExpose)示例详解

<template>
    <div class="Father">
        <p>我是父组件</p>
        <!--  -->
        <son :ftext="ftext"></son>
    </div>
</template>
<script setup>
import {ref} from 'vue'
import Son from './son.vue'
const ftext = ref('我是父组件-text')
</script>

<template>
    <div class="Son">
        <p>我是子组件</p>
       <!-- 展示来自父组件的值 -->
       <p>接收到的值：{{ftext}}</p>
    </div>
</template>
<script setup>
import {ref} from 'vue'
// setup 语法糖写法
 
//defineProps 来接收组件的传值
const props = defineProps({
    ftext: {
        type:String
    },
})
</script>

<template>
    <div class="Son">
        <p>我是子组件</p>
        <button @click="toValue">点击给父组件传值</button>
    </div>
</template>
    
<script setup>
import {ref} from 'vue'
// setup 语法糖写法
//用defineEmits()来定义子组件要抛出的方法,语法defineEmits(['要抛出的方法'])
const emit = defineEmits(['exposeData'])
 
const stext = ref('我是子组件的值-ftext')
const toValue = ()=>{
    emit('exposeData',stext)
}
    
</script>

<template>
    <div class="Father">
        <p>我是父组件</p>
        <!--  -->
        <son @exposeData="getData" :ftext="ftext"></son>
    </div>
</template>
    
<script setup>
import {ref} from 'vue'
import Son from './son.vue'
const ftext = ref('我是父组件-text')
const getData = (val)=>{
    console.log("接收子组件的值",val)
}
</script>

<template>
    <div>
        <p>我是子组件</p>
    </div>
</template>
    
<script setup>
import { ref } from 'vue';
 
    const stext = ref('我是子组件的值')
    const sfunction = ()=>{
        console.log("我是子组件的方法")
    }
    defineExpose({
        stext,
        sfunction
    })
</script>

<template>
	<div class="todo-container">
		<p>我是父组件</p>
		<son ref="sonDom"></son>
		<button @click="getSonDom">点击</button>
	</div>
</template>
 
<script setup>
import { ref ,nextTick} from 'vue';
	import son from './components/son.vue'
	const sonDom = ref(null) //注意这里的命名要和ref上面的命名一致
	const getSonDom = ()=>{
		console.log("sonDom",sonDom.value)
	}
 
	//直接打印sonDom的值是拿不到的，子组件节点还没生成
	nextTick(()=>{
		console.log("sonDom",sonDom.value)
	})
</script>