html js弹幕功能

本文主要是介绍html js弹幕功能，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

在这里插入图片描述
效果如上

html
<!DOCTYPE html>
<html><head><meta charset="utf-8" /><title></title><script charset="utf-8" src="https://unpkg.com/vue@2.6.14/dist/vue.min.js" type="text/javascript"></script><link rel="stylesheet" href="./css/index.css" /></head><body><div id="app"><div class="index" ref="index"><div class="btn stop" @click="stopDanmu">停止弹幕</div><div class="btn add" @click="adddanmu">添加弹幕</div></div></div></body><script src="./js/index.js"></script>
</html>

js
var app = new Vue({el: '#app',data: {list: [{text: '山河无恙，国泰民安'},{text: '我爱你，中国！'},{text: '辉煌七十五载，山河锦绣灿烂。'},{text: '生日快乐，我的国！'},{text: '清澈的爱，只为中国!'},{text: '岁月悠悠，山河如画!'},{text: '我爱中华！'},{text: '75年风雨兼程，共筑中国梦！'},{text: '鹭岛金秋红旗展，国庆佳节同欢庆'},{text: '泱泱中华, 千古风华依旧'},],windowWidth: '', // 屏幕的宽度marginLeft: 20, // 每一个距离左边的距离currentIndex: 0, // 当前弹幕列表的下标timeList: [], // 每一个弹幕的定时器currentDanmuNum: 0, // 当前的弹道addDanmuInterval:null, // 添加弹幕的定时器},mounted() {this.$nextTick(() => {this.windowWidth = document.querySelector('body').offsetWidththis.addDanmuInterval = setInterval(() => {// 获取弹幕总数 如果超过20个 不添加弹幕let danmuAllNum = document.querySelectorAll('.item').lengthif(danmuAllNum > 20) returnthis.addDanMuFn(this.list[this.currentIndex].text)this.currentIndex++if (this.currentIndex >= this.list.length) {this.currentIndex = 0}}, 1000)this.list.forEach((item, index) => {this.addDanMuFn(this.list[index].text)})// console.log(this.windowWidth);})},methods: {adddanmu() {this.addDanMuFn('添加新的弹幕', true)},stopDanmu() {// console.log(this.timeList);this.timeList.forEach(item => {clearInterval(item)// console.log(item);})clearInterval(this.addDanmuInterval)},addDanMuFn(text, isAddDanmu) {// 这里有个问题 添加太多计时器 就会错位 所以 弹幕量控制在 20以内this.$nextTick(() => {// 创建随机且唯一的弹幕类名idlet danmuName = 'danmu-' + this.randomString(6);// console.log(danmuName);// 生成弹幕的弹道 -- 随机弹道// let danmuNum = 'danmu-' + this.randomNum(0, 4)// 生成弹幕的弹道 -- 排序let danmuNum = 'danmu-' + this.currentDanmuNum;this.currentDanmuNum += 1if (this.currentDanmuNum > 4) {this.currentDanmuNum = 0}// console.log(danmuNum);// 获取 单前弹道的 所有元素let danmuNumAllDomNama = `.${danmuNum}`;let danmuNumAllDom = document.querySelectorAll(danmuNumAllDomNama)// 获取index元素let indexDom = document.querySelector('.index')// 判断当前弹道是否有元素if (danmuNumAllDom.length > 0) {// 获取最后一个元素let lastDom = danmuNumAllDom[danmuNumAllDom.length - 1]// 获取最后一个元素 本身的宽度let lastDomWidth = lastDom.offsetWidth;// 获取最后一个元素  距离左边的距离let lastDomLeft = lastDom.getBoundingClientRect().left;// 新的元素距离左边的距离let newDomLeft = lastDomWidth + lastDomLeft + this.marginLeft;if (newDomLeft < this.windowWidth) {newDomLeft = this.windowWidth}// 创建一个新的divlet div = document.createElement('div');if (isAddDanmu) {div.className = `${danmuName} ${danmuNum} item add`} else {div.className = `${danmuName} ${danmuNum} item`}div.style.left = newDomLeft + 'px';div.innerText = text;indexDom.appendChild(div);let currentDom = document.querySelector(`.${danmuName}`)let divWidth = currentDom.offsetWidth;danmuName = setInterval(() => {currentDom.style.left = currentDom.getBoundingClientRect().left - 1 +'px';if (currentDom.getBoundingClientRect().left < -divWidth) {clearInterval(danmuName)currentDom.remove()let index = this.timeList.findIndex(item => item == danmuName)this.timeList.splice(index,1)danmuName = nullindex = null}}, 10)this.timeList.push(danmuName)} else {// 单前弹道没有元素let newDomLeft = this.windowWidth;// 创建一个新的divlet div = document.createElement('div');if (isAddDanmu) {div.className = `${danmuName} ${danmuNum} item add`} else {div.className = `${danmuName} ${danmuNum} item`}div.style.left = newDomLeft + 'px';div.innerText = text;indexDom.appendChild(div);let currentDom = document.querySelector(`.${danmuName}`)let divWidth = currentDom.offsetWidth;danmuName = setInterval(() => {currentDom.style.left = currentDom.getBoundingClientRect().left - 1 +'px';if (currentDom.getBoundingClientRect().left < -divWidth) {clearInterval(danmuName)currentDom.remove()let index = this.timeList.findIndex(item => item == danmuName)this.timeList.splice(index,1)danmuName = nullindex = null}}, 10)this.timeList.push(danmuName)// console.log(div);}})},randomNum(a, b) {switch (arguments.length) {case 1:return parseInt(Math.random() * a + 1, 10);case 2:return parseInt(Math.random() * (b - a + 1) + a, 10);default:return 0}},randomString(a) {a = a || 32;var b = "";for (i = 0; i < a; i++)b += "ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678".charAt(Math.floor(48 * Math.random()));return b}},})

css
*{margin: 0;padding: 0;
}.index{width: 100vw;height: 100vh;background: #fff;position: relative;overflow: hidden;.btn{position: absolute;bottom: 0;width: 50vw;height: 30vw;font-size: 4vw;text-align: center;line-height: 30vw;&.stop{left: 0;}&.add{right: 0;}}.item{height: 10vw;padding: 0 3vw;border-radius: 10vw;background-color: gainsboro;color: #fff;font-size: 4vw;display: inline-block;position: absolute;text-wrap: nowrap;line-height: 10vw;&.add{background: red;}&.danmu-0{top: 0;}&.danmu-1{top: 12vw;}&.danmu-2{top: 24vw;}&.danmu-3{top: 36vw;}&.danmu-4{top: 48vw;}}
}