ref,computed 用法
<template> <div> <h1>{{count}}</h1> <h1>{{double}}</h1> <button @click="increase">+1</button> </div> </template>
<script lang="ts">
import { ref,computed } from 'vue'; export default { name: 'App', setup(){
const count = ref(0) const double = computed(()=>{ return count.value * 2 })
const increase = () => { count.value ++ } return { count, double, increase } } }; </script>