抽奖.html:

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<link rel="stylesheet" href="index.css">
<script type="text/javascript" src="index.js"></script>
</head>
<body>
<div id="title" class="title">开始抽奖啦</div>
<div class="btns">
<span id="play">开始</span>
<span id="stop">结束</span>
</div>
</body>
</html>
 
index.js代码如下：
var data=['iPhone5','IPad','三星笔记本','佳能相机','惠普打印机'],
timer = null,
flag=0;

window.onload = function(){
var play = document.getElementById('play'),
stop = document.getElementById('stop');

//开始抽奖
play.onclick=playFun;
stop.onclick = stopFun;

//键盘事件
document.onkeyup = function(event){
event = event || window.event;
console.log(event.keyCode);
if(event.keyCode==13)
{
if(flag==0){
playFun();
flag=1;
}
else {
stopFun();
flag = 0;
}
}
}
}

function playFun(){
//var that = this;
var title = document.getElementById('title');
var play = document.getElementById('play');
clearInterval(timer);
timer = setInterval(function(){
var random = Math.floor(Math.random()*data.length);
console.log(random);
title.innerHTML = data[random];
},50);
play.style.background ='#999';
}

function stopFun(){
clearInterval(timer);
var play = document.getElementById('play');
play.style.background ='#036';
}

index.css代码如下：
*
{
margin:0;
padding:0;
}

.title {
width:400px;
height:70px;
margin:0 auto;
padding-top:30px;
text-align:center;
font-size:24px;
font-weight:bold;
color:#F00;
}

.btns {
width:190px;
height:30px;
margin:0 auto;
}

.btns span {
display:block;
float:left;
width:80px;
height:27px;
line-height: 27px;
background:#036;
border:1px solid #eee;
border-radius:7px;
margin-right:10px;
color:#FFF;
text-align:center;
font-size:14px;
font-family:"微软雅黑";
cursor:pointer;
}