VIP30/v3_project/5_setup的细节/App.vue

<template>
  <h2>父级组件</h2>
  <h1>msg: {{ msg }}</h1>
  <button @click="msg += '==='">更新数据</button>
  <hr>
  <Child :msg = "msg"></Child>
</template>

<script lang="ts">
import { defineComponent,ref } from 'vue'
import Child from "./components/Child.vue"

export default defineComponent({
  setup () {
    const msg = ref('在干嘛')

    return {
      msg
    }
  },
  components: {
    Child
  }
})
</script>

<style scoped>

</style>