javascript-实现小抽奖程序

<style>
*{ margin: 0; padding:0;}
.prize_wrap{
	width: 300px;
	height: 150px;
}
.prize_wrap .active{	
	position: absolute;
	width: 100px;
	height: 50px;
	background: #f00;
	line-height: 50px;
	text-align: center;
	border:solid 1px #999;
	margin:-1px;
}
.prize_cell,
.prize_btn{
	position: absolute;
	background:#ccc;
	width: 100px;
	height: 50px;
	line-height: 50px;
	text-align: center;
}
.prize_btn{
	background:#f0f;
	cursor: pointer;
}
</style>
<div class="prize_wrap" id="prize_wrap">
	<div class="prize_cell" style="left:0;top:0">1</div>
    <div class="prize_cell" style="left:100px;top:0">2</div>
    <div class="prize_cell" style="left:200px;top:0">3</div>
    <div class="prize_cell" style="left:200px;top:50px">4</div>
	<div class="prize_btn"	style="left:100px;top:50px" id="prize_start">抽奖开始</div>
    <div class="prize_cell" style="left:200px;top:100px">5</div>
    <div class="prize_cell" style="left:100px;top:100px">6</div>
    <div class="prize_cell" style="left:0;top:100px">7</div>
    <div class="prize_cell" style="left:0;top:50px">8</div>
    
</div>
<script>
//构造函数
var prizeScroll=(function(doc){
	function _getItemsFilterCls(cls,items){
		var ret=[];
		for(var i=0,len=items.length;i<len;i++){
			if(items[i].className.indexOf(cls)>-1){				
				ret.push(items[i]);
			}	
		}
		return ret;
	}
	return function(opt){		
		this.wrap=doc.getElementById(opt.id)||doc.body;
		this.items=opt.items||_getItemsFilterCls(opt.id.replace(‘_wrap‘,‘‘)+‘_cell‘,this.wrap.getElementsByTagName(‘*‘));
		this.btn=doc.getElementById(opt.btn);
		this.curClass=opt.curClass||‘active‘;		
		this.prizeNum=-1;
		this.curIdx=0;
		this.interval=null;
		this.queue=[100,50,30,50,100,150];//转速
		this.queue.gid=0;//转圈数
		this.callBack=opt.callBack||function(){};
		this.init();
	}	
})(document);

//工具方法
prizeScroll.log=function(msg){
	if(console&&console.log){
		console.log(msg);	
	}else{
		alert(msg);	
	}
}


prizeScroll.prototype.init=function(){
	//初始化
	//prizeScroll.log(‘init‘);
}

prizeScroll.prototype._setInterval=function(timer,stopNum){
	//滚动动画
	var _self=this,len=stopNum||_self.items.length;
	_self._clearInterval();
	_self.interval=setInterval(function(){
		if(_self.curIdx>len-1){
			_self._clearInterval();
			_self._next();
			return;
		}
		_self._setActive(_self.curIdx);
		_self.curIdx++;
	},timer);
}
prizeScroll.prototype._setActive=function(idx){
	//设置中奖状态
	for(var i=0,len=this.items.length;i<len;i++){
		this.items[i].className=‘prize_cell‘;	
	}	
	this.items[idx].className=‘active‘;
}

prizeScroll.prototype._clearInterval=function(){
	//清除动画
	var _self=this;
	_self.interval&&clearInterval(_self.interval);
}
prizeScroll.prototype.start=function(){
	//开始
	this._next();
}
prizeScroll.prototype._next=function(){
	//动画排序
	this.curIdx=0;
	this.interval=null;
	var time=this.queue[this.queue.gid];
	if(this.queue.gid>this.queue.length-1){
		this.callBack(this.prizeNum);
		return;}
	if(this.queue.gid===this.queue.length-1){
		this._setInterval(time,this.getPrizeNum());//奖品设置
		this.queue.gid++;
		return;
	}	
	this._setInterval(time);
	this.queue.gid++;
}

prizeScroll.prototype.reset=function(){
	//重置重新开始
	this.stop();
	this.queue.gid=0;
}
prizeScroll.prototype.getPrizeNum=function(){
	//获取奖品号
	return this.prizeNum;
}
prizeScroll.prototype.setPrizeNum=function(prizeNum){
	//设置奖品号
	this.prizeNum=prizeNum;
}
prizeScroll.prototype.stop=function(){
	//停止
	//prizeScroll.log(‘stop‘);
	this._clearInterval();
}

var prizeAssembly={
	"1":"**币10枚",
	"2":"**币110枚",
	"3":"**币10枚",
	"4":"**币130枚",
	"5":"**币160枚",
	"6":"**币20枚",
	"7":"**币60枚",
	"8":"**币00枚"
}

var m=new prizeScroll({	
	id:‘prize_wrap‘,
	callBack:function(prizeNum){
		alert("您中了 "+prizeAssembly[prizeNum]+" ");
	}
})
document.getElementById(‘prize_start‘).onclick=function(){	
	m.setPrizeNum(1);
	m.start();
	//移除事件
	document.getElementById(‘prize_start‘).onclick=null;
}

</script>