3 - 响应性丟失 toRefs解决,问题涉及深拷贝

[zxxj]

<script setup lang="ts">
import { reactive, toRefs, toRef } from "vue"

function useCount() {
  const state = reactive({
    count: 0,
  })

  function update(value: number) {
    state.count = value
  }

  return {
    state: toRefs(state),
    update,
  }
}

// Ensure the destructured properties don't lose their reactivity
const { state: { count }, update } = useCount()
// 利用toRefs解决解构之后失去响应式问题,涉及深拷贝
</script>

<template>
  <div>
    <p>
      <span @click="update(count-1)">-</span>
      {{ count }}
      <span @click="update(count+1)">+</span>
    </p>
  </div>
</template>