<!-- 輪播wxml代碼 -->
<view class="teachers_banner">
 <view class="lunbo_center clearfix teachers_b">
  <view class="slide" id="slide" bindtouchstart='moveStart' bindtouchend='moveItem'>
   <ul>
    <block wx:for="{{datas}}" wx:key>
     <li animation="{{item.animation}}" style="z-index: {{item.zIndex}} ;opacity:{{item.opacity}};"
      bindtap="choose" data-id="{{item.id}}">
      <image src="{{item.iamge}}" />
     </li>
    </block>
   </ul>
  </view>
 </view>
</view>

/*輪播圖片*/
.lunbo_center {
 display: flex;
 flex-direction: column;
 align-items: center;
 justify-content: space-between;
 padding: 50rpx 0;
 box-sizing: border-box;
}
.teachers_b {
 position: relative;
}
#slide {
 margin: 0 auto;
 width: 100%;
 height: 160px;
 position: relative;
}
#slide li {
 position: absolute;
 width: 600rpx;
 height: 300rpx;
 display: -webkit-box;
 display: -webkit-flex;
 display: flex;
 align-items: flex-start;
 -webkit-box-align: flex-start;
 -webkit-align-items: flex-start;
 background: #fff;
 overflow: hidden;
 box-shadow: 0 0 20px #1d374d;
}
#slide li image {
 width: 100%;
 height: 100%;
}
.slide_left {
 width: 240px;
}
.slide_right {
 padding: 40px;
 -webkit-box-flex: 1;
 -webkit-flex: 1;
 flex: 1;
 min-width: 0;
}
.slide_right h3 {
 font: 400 30px/18px "Microsoft Yahei";
 color: #222;
}
.slide_right h3 span {
 display: inline-block;
 margin-left: 10px;
 font: 400 14px/36px "Microsoft Yahei";
 color: #555;
}
.slide_right p {
 padding: 20px 0 30px;
 color: #555;
 font: 400 14px/24px "Microsoft Yahei";
 border-bottom: 1px solid #dbdbdb;
}
.slide_right dl {
 padding-top: 30px;
}
.slide_right dd {
 /* float: left; */
 width: 33.3%;
 color: #777;
 font: 400 12px/24px "Microsoft Yahei";
}
.slide_right dd h3 {
 color: #ff9000;
 margin-bottom: 20px;
}
.arrow {
 display: none;
}
.arrow .prev, .arrow .next {
 position: absolute;
 width: 64px;
 top: 38%;
 z-index: 9;
 font: 700 96px 'simsun';
 opacity: 0.3;
 color: #fff;
 cursor: pointer;
}
.arrow .prev {
 left: -220px;
}
.arrow .next {
 right: -220px;
}
.arrow .prev:hover, .arrow .next:hover {
 color: #00a0e9;
 opacity: 0.7;
}

// js代碼
Page({
 /**
  * 頁面的初始數據
  */
 data: {
  startX: 0,
  endX: 0,
  iCenter: 3,
  datas: [{
   id: 1,
   zIndex: 2,
   opacity: 0.2,
   left: 10,
   iamge: "../../icon/lunbo2.jpg",
   animation: null
  },
  {
   id: 2,
   zIndex: 4,
   opacity: 0.4,
   left: 20,
   iamge: "../../icon/lunbo3.jpg",
   animation: null
  },
  {
   id: 3,
   zIndex: 6,
   opacity: 0.6,
   left: 30,
   iamge: "../../icon/lunbo4.jpg",
   animation: null
  },
  {
   id: 4,
   zIndex: 8,
   opacity: 1,
   left: 40,
   iamge: "../../icon/lunbo1.jpg",
   animation: null
  },
  {
   id: 5,
   zIndex: 6,
   opacity: 0.6,
   left: 50,
   iamge: "../../icon/lunbo2.jpg",
   animation: null
  },
  {
   id: 6,
   zIndex: 4,
   opacity: 0.4,
   left: 60,
   iamge: "../../icon/lunbo3.jpg",
   animation: null
  } ,
  {
   id: 7,
   zIndex: 2,
   opacity: 0.2,
   left: 70,
   iamge: "../../icon/lunbo1.jpg",
   animation: null
  }
  ],
  order: []
 },
 /**
  * 生命周期函數--監(jiān)聽頁面加載
  */
 onLoad: function (options) {
  this.__set__();
  this.move();
 },
 move: function () {
  var datas = this.data.datas;
  /*圖片分布*/
  for (var i = 0; i < datas.length; i++) {
   var data = datas[i];
   var animation = wx.createAnimation({
    duration: 100
   });
   animation.translateX(data.left).step();
   this.setData({
    ["datas[" + i + "].animation"]: animation.export(),
    ["datas[" + i + "].zIndex"]: data.zIndex,
    ["datas[" + i + "].opacity"]: data.opacity,
   })
  }
 },
 /**左箭頭 */
 left: function () {
  //
  var last = this.data.datas.pop(); //獲取數組的最后一個
  this.data.datas.unshift(last);//放到數組的第一個
  var orderFirst = this.data.order.shift();
  this.data.order.push(orderFirst);
  this.move();
 },
 /** */
 right: function () {
  var first = this.data.datas.shift(); //獲取數組的第一個
  this.data.datas.push(first);//放到數組的最后一個位置
  var orderLast = this.data.order.pop();
  this.data.order.unshift(orderLast);
  this.move();
 },
 /**點擊某項 */
 choose: function (e) {
  var that = this;
  var id = e.currentTarget.dataset.id;
  var order = that.data.order;
  var index = 0;
  for (var i = 0; i < order.length; i++) {
   if (id == order[i]) {
    index = i;
    break;
   }
  }
  if (index < that.data.iCenter) {
   for (var i = 0; i < that.data.iCenter - index; i++) {
    this.data.datas.push(this.data.datas.shift()); //獲取第一個放到最后一個
    this.data.order.unshift(this.data.order.pop());
    // this.right() 
   }
  } else if (index > that.data.iCenter) {
   for (var i = 0; i < index - that.data.iCenter; i++) {
    this.data.datas.unshift(this.data.datas.pop()); //獲取最后一個放到第一個
    this.data.order.push(this.data.order.shift());
    // this.left();
   }
  }
  this.move();
 },
 /**新的排列復制到新的數組中 */
 __set__: function () {
  var that = this;
  var order = that.data.order;
  var datas = that.data.datas;
  for (var i = 0; i < datas.length; i++) {
   that.setData({
    ["order[" + i + "]"]: datas[i].id
   })
  }
 },
 //手指觸發(fā)開始移動
 moveStart: function (e) {
  console.log(e);
  var startX = e.changedTouches[0].pageX;
  this.setData({
   startX: startX
  });
 },
 //手指觸摸后移動完成觸發(fā)事件
 moveItem: function (e) {
  console.log(e);
  var that = this;
  var endX = e.changedTouches[0].pageX;
  this.setData({
   endX: endX
  });
  //計算手指觸摸偏移劇距離
  var moveX = this.data.startX - this.data.endX;
  //向左移動
  if (moveX > 20) {
   this.left();
  }
  if (moveX < -20) {
   this.right();
  }
 },
})