安装库：cnpm install mitt

封装 eventbus.ts：

src->utils->eventbus.ts

//eventbus.ts

import mitt from 'mitt'

const emitter = mitt()

export default emitter

使用

B2.vue：

//B2.vue
<template>
    <div class="aa">
        <p>子组件B</p>
        <input v-model="info.name"><br>
        <input v-model="info.age"><br>
        <el-button type="primary" @click="emitB">派发一个事件</el-button>
    </div>
</template>

<script setup lang='ts'>
import { ref } from 'vue'
import emitter from '../utils/eventbus';

type tinfo = {
    name: string,
    age: number
}
const info = ref<tinfo>({ name: 'yyx', age: 12 })

const emitB = () => {
    emitter.emit('on-click', info.value)
}

</script>
<style scoped lang='scss'>
div {
    width: 400px;
    min-height: 300px;
    text-align: center;
    border: 1px solid #ccc;
    position: relative;
}
</style>

parent.vue：

//parent.vue
<template>
    <div>
        <p>这是父级</p>
        <span>==================================</span>

        <B2></B2>
        <C2 :info="_info"></C2>
    </div>
</template>

<script setup lang='ts'>
import { ref } from 'vue'
import emitter from '../utils/eventbus';
import B2 from '../components/B2.vue';
import C2 from '../components/C2.vue';

let _info = ref<unknown>(null)

emitter.on('on-click',(val)=>{
    _info.value = val
})


</script>
<style scoped lang='scss'></style>

C2.vue：

//C2.vue
<template>
    <div>组件3333333

        <p>name:{{ props?.info?.name }}</p>
        <p>age:{{ props?.info?.age }}</p>
    </div>
</template>

<script setup lang='ts'>


type tprops = {
    info?: any //有个问号?，是可选的参数，父组件在饮用的时候，可以不传
}
const props = withDefaults(defineProps<tprops>(), {
    info:{
        name:'张三',
        age:20
    }
})

</script>

<style scoped lang='scss'>
div {
    width: 400px;
    min-height: 300px;
    text-align: center;
    border: 1px solid #ccc;
}
</style>