vue3 手写tab栏的滑动效果

在tab上定位一个slider，每次点击的时候获取当前active的tab-item序号，从而获取到其相对于父元素的水平距离，然后把这个距离更新到slider的left属性上。

 代码存档↓

<template>
    <!-- tab组件封装 -->
  <div class="tab" style="margin-top: 10px;" >
    <div 
        class="tab-item" v-for="(item, index) in props.tabData" :key="index" 
        @click="handleTabChange(index)"
        :ref="el => {if(el)tabs[index] = el}"
    >
        {{ item.label }} 
    </div>
    <div class="slider" :style="`left: ${data.sliderPositionX}px`">{{ data.activeLabel }}</div>
</div>
</template>
 
<script setup>
import {onMounted, reactive, ref} from 'vue'
//父组件传递来的tab信息
const props = defineProps({
    tabData:{
        type:Object,
        validator: (value) => {
            return value.hasOwnProperty('label') && value.label !== ''
        }
 
    }
})
const emit = defineEmits(['returnCurrentIndex'])
const data = reactive({
    current: 1, //当前被选中的tab-item序号
    sliderPositionX: 0, //slider X轴方向位置
    windowWidth: window.innerWidth,
    activeLabel:''
})
const tabs = ref([])
 
//更改slider的位置
function updateSliderPosition(){
    let activeTab = tabs.value[data.current - 1]
    data.sliderPositionX = activeTab.offsetLeft
    data.activeLabel = props.tabData[data.current - 1].label
    console.log('tab', data.sliderPositionX)
}
 
function handleTabChange(index){
    data.current = index + 1
    //向父组件返回当前active tab的序号 方便对页面更新
    emit('returnCurrentIndex', data.current)
    updateSliderPosition()
}
 
onMounted(() => {
    updateSliderPosition()
    window.addEventListener('resize', () => updateSliderPosition());
})
 
</script>
 
<style scoped lang="scss">
    .tab{
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
        margin-bottom: 10px;
        position: relative;
        .tab-item{
            background-color: #353945;
            border: 1px solid #B1B5C3;
            color: #B1B5C3;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            font-size: 14px;
            padding: 8px 16px;
            box-sizing: border-box;
            width: 95px; 
            height: 40px;
            margin: 0;
        }
        .tab-item:first-child{
            border-radius: 2px 0 0 2px;
        }
        .tab-item:last-child{
            border-radius: 0 2px 2px 0;
        }
        .slider{
            position: absolute;
            top: 0;
            width: 95px;
            height: 40px;
            transition: left 0.5s;
            box-sizing: border-box;
            background: linear-gradient(to right, #F4A58A, #ED6B4E);
            color:#000;
            border: 1px solid transparent; 
            display: flex;
            align-items: center;
            justify-content: center;
        }
    }
</style>