为什么 list中的switch不能绑定id

<view>  
        <view v-for="(item,index) in insurData" :key="index">  
            <switch :id="index" @change="checkInsurStatus"  />  
        </view>  
    </view>

报错
chunk-vendors.js:4684 [Vue warn]: Invalid prop: type check failed for prop "id". Expected String with value "0", got Number with value 0.

强行转换为 String 就不报错 但是 change事件中 返回的id为空

<view v-for="(item,index) in insurData" :key="index">  
            <switch :id="String(index)" @change="checkInsurStatus"  />  
        </view>

{type: "change", timeStamp: 838122.1999999881, detail: {…}, target: {…}, currentTarget: {…}, …}
changedTouches: []
currentTarget: {id: "", offsetLeft: 15, offsetTop: 91, dataset: {…}}
detail: {value: true}
mp: {@warning: "mp is deprecated", type: "change", timeStamp: 838122.1999999881, detail: {…}, target: {…}, …}
preventDefault: ƒ preventDefault()
stopPropagation: ƒ stopPropagation()
target: {id: "", offsetLeft: 15, offsetTop: 91, dataset: {…}, value: true}
timeStamp: 838122.1999999881
touches: []
type: "change"