<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>01_弹幕.html</title>
<style>
*{
margin: 0px;
padding: 0px;
}
body{
width: 100%;
height: 100%;
}
#box{
height: 670px;
width: 100%;
background-color: #000;
position: relative;
}
.ball{
width: 30px;
height: 30px;
position: absolute;
border-radius: 15px;
}
</style>
</head>
<body>
<div id="box">
</div>
</body>
</html>
<script>
var box=document.getElementById("box");
var ball=document.documentElement.clientHeight||document.body.clientHeight;
box.style.height=ball+"px";
function fun(){
var div=document.createElement("div");
div.className="ball";
box.appendChild(div);
var r=Math.floor(Math.random()*255);
var g=Math.floor(Math.random()*255);
var b=Math.floor(Math.random()*255);
div.style.background='rgb('+r+','+g+','+b+')';
div.style.left=Math.floor(Math.random()*300)+800+"px";
div.style.top=Math.floor(Math.random()*ball)+"px";
var time=null;
var l=div.offsetLeft;
time=setInterval(function () {
l--;
if(l<=30){
clearInterval(time);
box.removeChild(div);
}
div.style.left=l+"px";
},1);
}
setInterval(fun,800);
</script>
结果如下：