<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>Js原生弹幕</title> <link rel="stylesheet" href=""> <style type="text/css" media="screen"> * { margin: 0px; padding: 0px } html, body { height: 100% } body { overflow: hidden; background-color: #FFF; text-align: center; } .flex-column { display: flex; flex-direction: column; justify-content: space-between;, align-items: center; } .flex-row { display: flex; flex-direction: row; justify-content: center; align-items: center; } .wrap { overflow: hidden; width: 70%; height: 600px; margin: 100px auto; padding: 20px; background-color: transparent; box-shadow: 0 0 9px #222; border-radius: 20px; } .wrap .box { position: relative; width: 100%; height: 90%; background-color: #000000; border-radius: 10px } .wrap .box span { position: absolute; top: 10px; left: 20px; display: block; padding: 10px; color: #336688 } .wrap .send { display: flex; width: 100%; height: 10%; background-color: #000000; border-radius: 8px } .wrap .send input { width: 40%; height: 60%; border: 0; outline: 0; border-radius: 5px 0px 0px 5px; box-shadow: 0px 0px 5px #d9d9d9; text-indent: 1em } .wrap .send .send-btn { width: 100px; height: 60%; background-color: #fe943b; color: #FFF; text-align: center; border-radius: 0px 5px 5px 0px; line-height: 30px; cursor: pointer; } .wrap .send .send-btn:hover { background-color: #4cacdc } </style> </head> <body> <div class="wrap flex-column"> <div class="box"> <video src="danmu.mp4" width="100%" height="100%" controls autoplay></video> </div> <div class="send flex-row"> <input type="text" class="con" placeholder="弹幕发送[]~(^v^)~*"> <div class="send-btn">发送</div> </div> </div> <!-- javascript 前端中能做什么 1.响应用户的操作 事件(键盘事件、鼠标事件) 2.操作dom元素(增删改查、属性操作、样式等) 3.数据交互 表单验证 ajax json jsonp 正则表达式 4.造轮子 mvvm mvc nodeJS jquery --> <!-- 需求分析 用户点击发送按钮 把input的内容展示到box里面 1.元素 .con .send-btn .box span(创建) 2.事件:点击事件 键盘事件 3.行为 1.点击.send-btn获取.con的内容 (1)规范发送信息 (2)禁止空及全空格 (3)存储value值 2.根据内容动态生成span标签 (1)创建节点document.createElement (2)改变节点内容innerHTML (3)节点 生成初始化位置等 (4)标签添加到oBox appendChild 3.message运动 (1)改变元素的left值 (2)定时器改变 setInterval (3)this代表当前弹幕 (4)弹幕left = 当前left-1 4.随机函数 Math.random 0-1 包括0但不包括1 (1)top (2)color (3)fontsize (4)textShadow (5)timing运动曲线 linear ease-out 5.业务完善 (1)过去的删除掉 停止计时器 删除自身 终止函数 (2)完善回车输入 在oCon上回车 发送弹幕 --> <script src="jquery.min.js" type="text/javascript"></script> <script> //1.获取元素 var oBox = document.querySelector('.box'); //获取.box元素 var oCon = document.querySelector('.con'); //获取input框 var oBtn = document.querySelector('.send-btn'); //获取发送按钮 var cW = oBox.offsetWidth; //获取box的宽度 var cH = oBox.offsetHeight; //获取box的高度 var message = ''; //弹幕内容初始化 oBtn.onclick = send; //点击发送 oCon.onkeydown = function (e) { e = e || window.event; if (e.keyCode === 13) { //回车键 send(); } }; function send() { //获取oCon的内容 if (oCon.value.length <= 0 || (/^s+$/).test(oCon.value)) { alert('请输入弹幕'); return false; } message = oCon.value; console.log(message); //生成标签 createEle(message); //执行节点创建模块 oCon.value = ''; //收尾工作清空输入框 } function createEle(txt) { //动态生成span标签 var oMessage = document.createElement('span'); //创建标签 oMessage.innerHTML = txt; //接收参数txt并且生成替换内容 oMessage.style.left = cW + 'px'; //初始化生成位置x oBox.appendChild(oMessage); //把标签塞到oBox里面 roll.call(oMessage, { //call改变函数内部this的指向 timing: ['linear', 'ease-out'][~~(Math.random() * 2)], color: '#' + (~~(Math.random() * (1 << 24))).toString(16), top: random(0, cH), fontSize: random(16, 32) }); } function roll(opt) { //弹幕滚动 //如果对象中不存在timing 初始化 opt.timing = opt.timing || 'linear'; opt.color = opt.color || '#fff'; opt.top = opt.top || 0; opt.fontSize = opt.fontSize || 16; this._left = parseInt(this.offsetLeft); //获取当前left的值 this.style.color = opt.color; //初始化颜色 this.style.top = opt.top + 'px'; this.style.fontSize = opt.fontSize + 'px'; this.timer = setInterval(function () { if (this._left <= 100) { clearInterval(this.timer); //终止定时器 this.parentNode.removeChild(this); return; //终止函数 } switch (opt.timing) { case 'linear': //如果匀速 this._left += -2; break; case 'ease-out': // this._left += (0 - this._left) * .01; break; } this.style.left = this._left + 'px'; }.bind(this), 1000 / 60); } function random(start, end) { //随机数封装 return start + ~~(Math.random() * (end - start)); } var aLi = document.querySelectorAll('li'); //10 function forEach(ele, cb) { for (var i = 0, len = aLi.length; i < len; i++) { cb && cb(ele[i], i); } } forEach(aLi, function (ele, i) { ele.style.left = i * 100 + 'px'; }); //产生闭包 var obj = { num: 1, add: function () { this.num++; //obj.num = 2; (function () { console.log(this.num); }) } }; obj.add(); //window </script> </body> </html>