一、用到的图片
二、代码如下，重点是js部分
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>jQuery九宫格大转盘抽奖</title>
<style>
#lottery{width:570px;height:510px;margin:0px auto;border:4px solid #ba1809;}
#lottery table{background-color:yellow;}
#lottery table td{position:relative;width:190px;height:170px;text-align:center;color:#333;font-index:-999}
#lottery table td img{display:block;width:190px;height:170px;}
#lottery table td a{width:190px;height:170px;display:block;text-decoration:none;background:url(images/lottery1.jpg) no-repeat top center;}
#lottery table td a:hover{background-image:url(images/lottery2.jpg);}
#lottery table td.active .mask{display:block;}
.mask{
width:100%;
height:100%;
position:absolute;
left:0;
top:0;
background:url(images/mask.png) no-repeat;
display:none;
}
</style>
</head>
<body class="keBody">
<!--效果html开始-->
<div id="lottery">
<table border="0" cellpadding="0" cellspacing="0">
<tr>
<td class="lottery-unit lottery-unit-0"><img src="images/gift0.jpg"><div class="mask"></div></td>
<td class="lottery-unit lottery-unit-1"><img src="images/gift1.jpg"><div class="mask"></div></td>
<td class="lottery-unit lottery-unit-2"><img src="images/gift2.jpg"><div class="mask"></div></td>
</tr>
<tr>
<td class="lottery-unit lottery-unit-7"><img src="images/gift7.jpg"><div class="mask"></div></td>
<td><a href="#"></a></td>
<td class="lottery-unit lottery-unit-3"><img src="images/gift3.jpg"><div class="mask"></div></td>
</tr>
<tr>
<td class="lottery-unit lottery-unit-6"><img src="images/gift6.jpg"><div class="mask"></div></td>
<td class="lottery-unit lottery-unit-5"><img src="images/gift5.jpg"><div class="mask"></div></td>
<td class="lottery-unit lottery-unit-4"><img src="images/gift4.jpg"><div class="mask"></div></td>
</tr>
</table>
</div>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<script type="text/javascript">
var lottery={
index:-1, //当前转动到哪个位置，起点位置
count:0, //总共有多少个位置
timer:0, //setTimeout的ID，用clearTimeout清除
speed:20, //初始转动速度
times:0, //转动次数
cycle:50, //转动基本次数：即至少需要转动多少次再进入抽奖环节
prize:-1, //中奖位置
init:function(id){
if ($("#"+id).find(".lottery-unit").length>0) {
$lottery = $("#"+id);
$units = $lottery.find(".lottery-unit");
this.obj = $lottery;
this.count = $units.length;
$lottery.find(".lottery-unit-"+this.index).addClass("active");
};
},
roll:function(){
var index = this.index;
var count = this.count;
var lottery = this.obj;
$(lottery).find(".lottery-unit-"+index).removeClass("active");
index += 1;
if (index>count-1) {
index = 0;
};
$(lottery).find(".lottery-unit-"+index).addClass("active");
this.index=index;
return false;
},
stop:function(index){
this.prize=index;
return false;
}
};
function roll(){
lottery.times += 1;
lottery.roll();//转动过程调用的是lottery的roll方法，这里是第一次调用初始化
if (lottery.times > lottery.cycle+10 && lottery.prize==lottery.index) {
clearTimeout(lottery.timer);
lottery.prize=-1;
lottery.times=0;
click=false;
}else{
if (lottery.times<lottery.cycle) {
lottery.speed -= 10;
}else if(lottery.times==lottery.cycle) {
var index = Math.random()*(lottery.count)|0;
lottery.prize = index;
}else{
if (lottery.times > lottery.cycle+10 && ((lottery.prize==0 && lottery.index==7) || lottery.prize==lottery.index+1)) {
lottery.speed += 110;
}else{
lottery.speed += 20;
}
}
if (lottery.speed<40) {
lottery.speed=40;
};
//console.log(lottery.times+'^^^^^^'+lottery.speed+'^^^^^^^'+lottery.prize);
lottery.timer = setTimeout(roll,lottery.speed);//循环调用
}
return false;
}
var click=false;
window.onload=function(){
lottery.init('lottery');
$("#lottery a").click(function(){
if (click) {//click控制一次抽奖过程中不能重复点击抽奖按钮，后面的点击不响应
return false;
}else{
lottery.speed=100;
roll(); //转圈过程不响应click事件，会将click置为false
click=true; //一次抽奖完成后，设置click为true，可继续抽奖
return false;
}
});
};
</script>
<!--效果html结束-->
</body>
</html>
效果如下：
三、注意事项
.mask开始如下，用的是rgba，但是IE8不兼容，改为使用png图片background:url(images/mask.png) no-repeat;
.mask {
width: 100%;
height: 100%;
position: absolute;
left: 0;
top: 0;
background-color: rgba(252,211,4,0.5);
display: none
}
jQuery+Ajax九宫格抽奖转盘
分享一款jQuery九宫格大转盘抽奖代码网页特效，点击抽奖按钮开始随机抽奖选择奖品，可设置起点位置、奖品数量、转动次数、中奖位置参数，并且后台ajax.php可设置奖品和中奖概率。
首先我们在#lottery放置12个奖品，代码如下：
点击“开始抽奖”按钮，并且远程ajax.php获取奖项：
$(function() {
lottery.init('lottery');
$("#lottery a").click(function() {
if (click) {
return false;
} else {
lottery.speed = 100;
$.post("ajax.php", {
uid: 1
},
function(data) { //获取奖品，也可以在这里判断是否登陆状态
$("#lottery").attr("prize_site", data.prize_site);
$("#lottery").attr("prize_id", data.prize_id);
$("#lottery").attr("prize_name", data.prize_name);
roll();
click = true;
return false;
},
"json")
}
});
})
Ajax.php
12个奖品数组如下，其中prize表示奖项内容，v表示中奖几率(若数组中七个奖项的v的总和为100，如果v的值为1，则代表中奖几率为1%，依此类推)
$prize_arr = array(
'0' => array('id' => 1, 'prize' => '一等奖', 'v' => 5),
'1' => array('id' => 2, 'prize' => '二等奖', 'v' => 5),
'2' => array('id' => 3, 'prize' => '三等奖', 'v' => 5),
'3' => array('id' => 4, 'prize' => '四等奖', 'v' => 5),
'4' => array('id' => 5, 'prize' => '五等奖', 'v' => 5),
'5' => array('id' => 6, 'prize' => '六等奖', 'v' => 5),
'6' => array('id' => 7, 'prize' => '七等奖', 'v' => 5),
'7' => array('id' => 8, 'prize' => '八等奖', 'v' => 5),
'8' => array('id' => 9, 'prize' => '九等奖', 'v' => 5),
'9' => array('id' => 10, 'prize' => '十等奖', 'v' => 5),
'10' => array('id' => 11, 'prize' => '十一等奖', 'v' => 25),
'11' => array('id' => 12, 'prize' => '十二等奖', 'v' => 25),
);
获取随机奖品：
foreach ($prize_arr as $k=>$v) {
$arr[$v['id']] = $v['v'];
}
$prize_id = getRand($arr); //根据概率获取奖项id
foreach($prize_arr as $k=>$v){ //获取前端奖项位置
if($v['id'] == $prize_id){
$prize_site = $k;
break;
}
}
$res = $prize_arr[$prize_id - 1]; //中奖项
$data['prize_name'] = $res['prize'];
$data['prize_site'] = $prize_site;//前端奖项从-1开始
echo json_encode($data);