【报Bug】微信小程序输入框BUG

示例代码：

<template>  
    <view class="wrap">  
        <view class="top"><u-search @custom="searchList" @search="searchList" placeholder="请输入搜索条件" v-model="keyword"></u-search></view>  
        <loading-list top="80rpx" bottom="100rpx" ref="list" url="/stock" class="member-list">  
            <view slot="list" slot-scope="{ list }">  
                <view v-for="(item, index) in list" :key="index" class="member-item">  
                    <view class="member-left">  
                        <view class="avatar-box"  :style="{'background-color':getRandomColor( item )}">  
                            {{ item.Name[0] }}  
                        </view>  
                    </view>  
                    <view class="member-info">  
                        <view>{{ item.Name }}</view>  
                        <view>{{ item.Price }}/{{ item.Specs }}</view>  
                        <view>库存: {{ item.Quantity }}</view>  
                    </view>  
                    <view class="ico"><u-icon name="arrow-right" color="#909399" size="20"></u-icon></view>  
                </view>  
            </view>  
        </loading-list>  
    </view>  
</template>  

<script>  
import LoadingList from '@/components/page-lists/loading-list.vue';  

export default {  
    data() {  
        return {  
            listData: [],  
            listQuery: {},  
            keyword: ''  
        };  
    },  
    components: {  
        LoadingList  
    },  
    computed: {  

    },  
    methods: {  
        searchList() {  
            this.listQuery = {  
                Name: this.keyword  
            };  
            this.$refs.list.loadList(this.listQuery, true);  
        },  
        getRandomColor(item) {  
            console.log(item)  
                    const rgb = []  
                    for (let i = 0; i < 3; ++i) {  
                        let color = Math.floor(Math.random() * 256).toString(16)  
                        color = color.length == 1 ? '0' + color : color  
                        rgb.push(color)  
                    }  
                    return '#' + rgb.join('')  
                }  
    }  
};  
</script>  

<style lang="scss" scoped>  
@import './index.scss';  
</style>  

操作步骤：

v-for循环遍历数组，并且给每个创建的图片组件设置一个随机背景色，randomColor每执行一个都会返回一个随机的rgb颜色，但是这个方法被多次执行。

预期结果：

输入文字时randomColor方法不执行

实际结果：

输入文字时randomColor方法执行