多宫格抽奖活动的实现

<view class="box">
 <view class="boxsub {{luckynum==index?&#39;luck&#39;:&#39;&#39;}}" wx:for=&#39;{{box}}&#39; style="{{index>0&&index<4?&#39;top:0;left:&#39;+index*140+&#39;rpx;&#39;:(index>3&&index<8?&#39;right:0;
 top:&#39;+((index-4)*100)+&#39;rpx;&#39;:(index>7&&index<12?&#39;bottom:0;right:&#39;+(index-7)*140+&#39;rpx;&#39;:(index>11&&index<14?&#39;left:0;bottom:&#39;+(index-11)*100+&#39;rpx;&#39;:&#39;&#39;)))}} 
 {{index==&#39;4&#39;?&#39;top:0;&#39;:&#39;&#39;}} {{index==&#39;11&#39;?&#39;left:0;&#39;:&#39;&#39;}} " wx:key=&#39;&#39;>
   <text class=&#39;boxcontent&#39; style=&#39;{{item.name.length>6?"line-height:40rpx;margin-top:10rpx;":"line-height:100rpx;"}}&#39;>{{item.name}}</text> 
  
 </view>
 <view class="lucky" catchtap="luckyTap">
  <text class="taplucky">点击抽奖</text>
  <text class="howMany">您还有<text class="howMany_num" >{{howManyNum}}</text>次抽奖机会</text>
 </view>
</view>
<view class="explain">

</view>

.box{
 margin:20rpx 25rpx;
 height: 400rpx;
 width: 698rpx;
 /*border:1px solid #ddd;*/
 position: relative;
 /*box-sizing: border-box;*/
}
.boxsub{
 width: 140rpx;
 height: 100rpx;
 /*border: 1px solid #f00;*/
 box-sizing: border-box;
 position: absolute;
 background: #ff6100;
 border: 1rpx solid #fff;
 
}
.boxcontent{
 text-align: center;
 font-size: 26rpx;
 display: block;
 color: #fff;
}
.lucky{
 width: 300rpx;
 height:130rpx;
 background:#ff6100;/* #ff6100;007FFF*/
 position: absolute;
 left: 0;
 bottom: 0;
 right: 0;
 top: 0rpx;
 margin: auto;
}

.lucky:active{
 opacity: 0.7;
}
.taplucky{
 display: block;
 text-align: center;
 font-size: 30rpx;
 line-height: 50rpx;
 height: 50rpx;
 color: #fff;
 margin-top: 20rpx;
}
.howMany{
 display: block;
 text-align: center;
 font-size: 26rpx;
 color: #fff;
 line-height: 40rpx;
 height: 40rpx;
}
.howMany_num{
 color:#007FFF;
 font-size:32rpx;
 line-height:40rpx;
 padding:0 10rpx;
}
.luck{
 opacity: 0.5;
 background: #ff6100;
}

var time = null;//setTimeout的ID，用clearTimeout清除
Page({
 data: {
 box: [{
  name:'100积分'
 }, {
  name: '10元优惠券\n满100可用'
 }, {
  name: '60积分'
 }, {
  name: '30积分'
 }, {
  name: '50积分'
 }, {
  name: '30元优惠券\n满120可用'
 }, {
  name: '100积分'
 }, {
  name: '200积分'
 }, {
  name: '10积分'
 }, {
  name: '50积分'
 }, {
  name: '40积分'
 }, {
  name: '50优惠券满500可用'
 }, {
  name: '60积分'
 }, {
  name: '70积分'
 }],
 luckynum:0,//当前运动到的位置，在界面渲染
 howManyNum:10,//抽奖的剩余次数
 content:{
  index: 0, //当前转动到哪个位置，起点位置
  count: 0, //总共有多少个位置
  speed: 50, //初始转动速度
  cycle: 3*14, //转动基本次数：即至少需要转动多少次再进入抽奖环节，这里设置的是转动三次后进入抽奖环节
 },
 prize:0,//中奖的位置
 luckytapif:true//判断现在是否可以点击
 },
 //点击抽奖
 luckyTap:function(){
 var i=0,
  that=this,
  howManyNum = this.data.howManyNum,//剩余的抽奖次数
  luckytapif = this.data.luckytapif,//获取现在处于的状态
  luckynum = this.data.luckynum,//当前所在的格子
  prize =Math.floor(Math.random()*14) ;//中奖序号,随机生成
 if (luckytapif && howManyNum>0){//当没有处于抽奖状态且剩余的抽奖次数大于零，则可以进行抽奖
  console.log('prize:'+prize);
  this.data.content.count=this.data.box.length;
  this.setData({
  howManyNum:howManyNum-1//更新抽奖次数
  });
  this.data.luckytapif=false;//设置为抽奖状态
  this.data.prize = prize;//中奖的序号
  this.roll();//运行抽奖函数
 } else if (howManyNum == 0 && luckytapif){
  wx.showModal({
  title: '',
  content: '您的抽奖次数已经没有了',
  showCancel:false
  })
 }
 },
//抽奖
 roll:function(){
 var content=this.data.content,
  prize = this.data.prize,//中奖序号
  that=this;
 if (content.cycle - (content.count-prize)>0){//最后一轮的时间进行抽奖
  content.index++;
  content.cycle--;
  this.setData({
  luckynum: content.index%14 //当前应该反映在界面上的位置
  });
  setTimeout(this.roll, content.speed);//继续运行抽奖函数
 }else{
  if (content.index < (content.count*3 + prize)){//判断是否停止

  content.index++; 
  content.speed += (550 /14);//最后一轮的速度，匀加速，最后停下时的速度为550+50
  this.data.content=content;
  this.setData({
   luckynum: content.index % 14
  });
  console.log(content.index, content.speed);//打印当前的步数和当前的速度
  setTimeout(this.roll,content.speed);
  }else{
  //完成抽奖，初始化数据
  console.log(&#39;完成&#39;);
  content.index =0;
  content.cycle = 3 * 14;
  content.speed = 50;
  this.data.luckytapif = true;
  clearTimeout(time);
  wx.showModal({
   title: &#39;&#39;,
   content: &#39;恭喜你抽到了&#39;+that.data.box[prize].name,
   showCancel:false
  })
  }
 }
 },
 onLoad: function (options) {
 
 },
 onReady: function () {
 
 },
 onShow: function () {
 
 },
 onHide: function () {
 
 },
 onUnload: function () {
 
 }
})