The parent component accesses the methods or parameters of the child component (the child component exposes the method defineexpose)

Parent component

<template>
    <div> 
          <Menu ref="menus"  @onclick3="getList3"/>   
          
    </div>
</template>

<script setup lang="ts">
import {
    reactive ,ref}  from 'vue'  
const  menus=ref(null)  //const The name of the ref Consistency of definition 
interface jianc{
    
    title:string
}
const getList3=()=>{
     
// Taken ref Parameters under sub components list [6,6,6,6] //
    console.log(menus.value.list.map(v=>v))

}

</script>

<style scoped>

</style>

Child components （ Child components emit Submit a custom event After the parent component is triggered Get ref Parameters under sub components list[6,6,6,6]）

<template>
   <div class="">
      <button @click="clickTap3"> distributed 3</button>
   </div> 
</template>

<script setup lang="ts">
import  {
    reactive,  defineEmits, defineExpose}  from 'vue';

const list=reactive<number[]>([6,6,6,6])//number The array value of type is [6,6,6,6]
const emit=defineEmits(['onclick3']);
const onclick3=()=>{
    
	emit('onclick3')
}
//  Send out the sub components ([6,6,6,6])  Parent component takes 
defineExpose({
    
    list
})
</script>

<style scoped>
.menu{
    
    width: 100px;text-align: center;
    border: 1px solid #000;
    height: 100vh;
}
</style>