vue3中给数组赋值丢失响应式的解决

const arr = reactive([]);
 
const load = () => {
  const res = [2, 3, 4, 5]; //假设请求接口返回的数据
  // 方法1 失败，直接赋值丢失了响应性
  // arr = res;
  // 方法2 这样也是失败
  // arr.concat(res);
  // 方法3 可以，但是很麻烦
  res.forEach(e => {
    arr.push(e);
  });
  // 方法4 可以
  // arr.length = 0 // 清空原数组
  arr.push(...res)
}

const state = reactive({
	arr: []
});
...
state.arr = res
...

const state = ref([]);
...
state.value= res
...

<template>
    <div class="content">
		...
        <Card title="content组件">
            <button @click.prevent="add">ADD</button>
            <button @click.prevent="pop">POP</button>
            <button @click.prevent="changeList">changeList</button>
            {{ list }}
            <ProInj></ProInj>
        </Card>
    </div>
</template>

<script setup lang="ts">
import { reactive, markRaw, ref, defineAsyncComponent, inject, Ref } from 'vue'
...
let flag = ref(true)

let list = inject<Ref<number[]>>('list',ref(reactive<number[]>([])))
// let list = inject<Ref<number[]>>('list', ref<number[]>([1, 2, 3]))
const add = () => list.push(list!.length + 1)
const pop = () => list.pop()

const changeList = () => {
    flag.value = !flag.value
    if (flag.value) {
        list.length = 0
        list.push(...[9, 5, 4, 1])
    }
    else {
        list.length = 0
        list.push(...[6, 6, 6, 6, 6])
    }
}
...
</script>

<style lang="less" scoped>
...
</style>

const  list = reactive({})

    const  list = reactive({
    arr:[]
})

list.arr = data.arr

const list = ref([])
list.value = data