正确实例(采用readonly)

父组件 : 

<template>
  <div>
      父组件 : {{data.name}} - {{data.age}} - {{data.hight}}
      <hr>
      <Hello :data="data" :readonlyData="readonlyData" @readonlyChange="readonlyChange"></Hello>
  </div>
</template>

<script>
import Hello from './components/Hello.vue'
import {reactive, readonly} from 'vue'
export default {
  components:{
    Hello
  },
  setup(){
    const data = reactive({
      name:'吴宇腾',
      age:39,
      hight:1.88
    })

    // 采用readonly
    const readonlyData = readonly(data)
    // 自定义事件
    const readonlyChange  = (name,age)=>{
      data.name = name 
      data.age += age
    }

    return {
      data,
      readonlyData,
      readonlyChange
    }
  }
}
</script>

子组件 : 

<template>
  <div>
    子组件 : {{data.name}} - {{data.age}} - {{data.hight}}
    <br>
    <button @click="data.name = '杨浩楠' ,data.age++">错误师范,不知道单向数据流,直接修改传递过来的值</button>
    
    <hr>
    
    子组件采用readonly : {{readonlyData.name}} - {{readonlyData.age}} - {{readonlyData.hight}}
    <button @click="readonlyData.name = '杨浩楠' ,readonlyData.age++">采用readonly,想直接修改,不行</button>
    
    <button @click="readonlyChange"> 正确修改 : 传递给父组件 </button>
  </div>

</template>

<script>
export default {
    name:'Hello',
    props:['data','readonlyData'],
    setup(props,context){
      
      // 发送自定义事件
      const readonlyChange = ()=>{
        context.emit('readonlyChange','杨浩楠ro',1)
      }
      
      return {
        readonlyChange
      }
    }
}
</script>

<style>

</style>