跑马灯的两种实现方式

方式一：利用元素尺寸变化监听api，计算宽度，得出时间，进行无限次数动画。

优点：能自定义速度（0 - 1）。

<template>
    <div class="box">
        <i class="iconfont icon-gonggao"></i>
        <div class="marquee-box">
            <div ref="elRef" class="marquee">
                <slot></slot>
            </div>
        </div>
    </div>
</template>
<script setup lang="ts">
import { onMounted, ref } from 'vue';
const props = defineProps({
    speed: {
        type: Number,
        default: 0.1
    },
})
const elRef = ref()

onMounted(() => {
    marquee(elRef.value, props.speed)
})

function marquee(el: HTMLElement, speed: number = 0.1) {
    const startMarquee = () => {
        const parentWidth = parseInt(window.getComputedStyle(el?.parentNode).width)
        const allWidth = window.innerWidth + parseInt(window.getComputedStyle(el).width)
        const _speed = speed >= 1 ? 0.99 : speed <= 0 ? 0.01 : speed;
        const time = allWidth * 30000 / 1920 * (1 - _speed);

        el.animate([
            { transform: `translateX(${parentWidth}px)` },
            { transform: `translateX(-100%)`}
        ], {
            duration: time,
            easing: 'linear',
            iterations: Infinity,
        })
    }
    const ro= new ResizeObserver((entries, observer) => {
        startMarquee()
    });
    ro.observe(el);
}
</script>
<style lang="less" scoped>
    .box{
        display: flex;
        align-items: center;
        padding: 1.875rem 0 1.875rem 1rem;
        background-color: #FFF8EE;
        color: #FC7D3C;
        font-size: 18px;
        .marquee-box{
            flex: 1;
            min-width: 0px;
            margin-left: .2rem;
            overflow: hidden;
        }
        .marquee{
            display: inline-block;
            white-space:nowrap;
        }
        .iconfont{
            font-size: 1.875rem;
            line-height: 1;
        }
    }
    .h5{
        .box{
            padding: .5rem 0;
            font-size: 0.875rem;
        }
        .iconfont{
            font-size: 1.2rem;
        }
    }
</style>

方式二：利用原生跑马灯标签，简单。

缺点：不能定义速度。

<template>
    <div class="box">
        <i class="iconfont icon-gonggao"></i>
        <marquee bgcolor= "#FFF8EE">
            <slot></slot>
        </marquee>
    </div>
</template>
<style lang="less" scoped>
    .box{
        display: flex;
        align-items: center;
        padding: 1.875rem 0 1.875rem 1rem;
        background-color: #FFF8EE;
        color: #FC7D3C;
        font-size: 18px;
        .iconfont{
            font-size: 1.875rem;
            line-height: 1;
        }
    }
    .h5{
        .box{
            padding: .5rem 0;
            font-size: 0.875rem;
        }
        .iconfont{
            font-size: 1.2rem;
        }
    }
</style>