html文件：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>弹幕效果</title>
<style>
html, body {
margin: 0px;
padding: 0px;
100%;
height: 100%;
font-family: "微软雅黑";
font-size: 62.5%;
}
.boxDom {
100%;
height: 100%;
position: relative;
overflow: hidden;
}
.idDom {
100%;
height: 100px;
background: #666;
position: fixed;
bottom: 0px;
}
.content {
display: inline-block;
430px;
height: 40px;
position: absolute;
left: 0px;
right: 0px;
top: 0px;
bottom: 0px;
margin: auto;
}
.title {
display: inline;
font-size: 4em;
vertical-align: bottom;
color: #fff;
}
.text {
border: none;
300px;
height: 30px;
border-radius: 5px;
font-size: 2.4em;
}
.btn {
60px;
height: 30px;
background: #f90000;
border:none;
color: #fff;
font-size: 2.4em;
}
span {
300px;
height: 40px;
position: absolute;
overflow: hidden;
color: #000;
font-size: 4em;
line-height: 1.5em;
cursor: pointer;
white-space: nowrap;
}
</style>
</head>
<body>
<div class="boxDom" id="boxDom">
<div class="idDom" id="idDom">
<div class="content">
<p class="title">吐槽:</p>
<input type="text" class="text" id="text"/>
<button type="button" class="btn" id="btn">发射</button>
</div>
</div>
</div>
</body>
<script src="jquery-1.12.4.js"></script>
<script>
$(function(){
//注册事件
var colors = ["red","green","hotpink","pink","cyan","yellowgreen","purple","deepskyblue"];
$("#btn").click(function(){
var randomColor = parseInt(Math.random() * colors.length);
var randomY = parseInt(Math.random() * 400);
$("<span></span>")//创建span
.text($("#text").val())//设置内容
.css("color",colors[randomColor])//设置字体颜色
.css("left","1400px")//设置left值
.css("top",randomY)//设置top值
.animate({left:-500},10000,"linear",function(){
//到了终点，需要删除
$(this).remove();
})//添加动画
.appendTo("#boxDom");
$("#text").val("");
});
$("#text").keyup(function(e){
if (e.keyCode == 13) {
$("#btn").click();
}
});
});
</script>
</html>
