jquery转盘抽奖功能实现

时间:2020-05-14 starof 人气:0

一、用到的素材

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
}

希望大家可以从小编整理的这篇文章中有所收获，对大家实现抽奖功能有所帮助。

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