vue3学习总结

setup返回的对象数据如果想被模版正确解析，必须是一个ref函数返回的类型

<template>
  <div>
    <h1>{{ count }}</h1>
    <div>{{double}}</div>
    <button @click="increase">add</button>
  </div>
</template>

<script lang="ts">
import { ref, computed } from 'vue'
export default {
  name: 'HelloWorld',
  setup () {
    const count = ref(0)
    const double = computed(() => {
      return count.value * 2
    })
    const increase = () => {
      count.value++
    }
    return {
      count,
      increase,
      double
    }
  }
}
</script>

但此时会发现代码写起来很麻烦

<template>
  <div>
    <h1>{{ count }}</h1>
    <div>{{double}}</div>
    <button @click="increase">add</button>
  </div>
</template>

<script lang="ts">
import { computed, reactive, toRefs } from 'vue'
export default {
  name: 'HelloWorld',
  setup () {
    const data = reactive({
      count: 0,
      increase: () => {
        data.count++
      },
      double: computed(() => { return data.count * 2})
    })
    const refData = toRefs(data)
    return {
      ...refData
    }
  }
}
</script>