详解iview的checkbox多选框全选时校验问题

<template>  <div style="border-bottom: 1px solid #e9e9e9;padding-bottom:6px;margin-bottom:6px;">    <Checkbox      :indeterminate="indeterminate"      :value="checkAll"      **@click.prevent.native="handleCheckAll"**>全选</Checkbox>  </div>  <CheckboxGroup v-model="checkAllGroup" @on-change="checkAllGroupChange">    <Checkbox label="香蕉"></Checkbox>    <Checkbox label="苹果"></Checkbox>    <Checkbox label="西瓜"></Checkbox>  </CheckboxGroup></template><script>  export default {    data () {      return {        indeterminate: true,        checkAll: false,        checkAllGroup: ['香蕉', '西瓜']      }    },    methods: {      handleCheckAll () {        if (this.indeterminate) {          this.checkAll = false;        } else {          this.checkAll = !this.checkAll;        }        this.indeterminate = false;        if (this.checkAll) {          this.checkAllGroup = ['香蕉', '苹果', '西瓜'];        } else {          this.checkAllGroup = [];        }      },      checkAllGroupChange (data) {        if (data.length === 3) {          this.indeterminate = false;          this.checkAll = true;        } else if (data.length > 0) {          this.indeterminate = true;          this.checkAll = false;        } else {          this.indeterminate = false;          this.checkAll = false;        }      }    }  }</script>