微信小程序实现左滑动删除效果

<view class="touch-item {{item.isTouchMove ? 'touch-move-active' : ''}}" data-index=" {{index}}" bindtouchstart="touchstart" bindtouchmove="touchmove" wx:for="{{items}}" wx:key="">
 <view class="content">
 <view class='com'>
 <view class='tp'>
  <image src="{{item.image_src}}" class='img' />
 </view>
 <view class='txt'>
  <view class='tit'>{{item.goods_name}}</view>

  <view class='bot'>

  <block wx:if="{{item.marketable=='true'}}">
  <view class="pri">
  <text class="new-price">￥{{item.goods_price}}</text>
  <text class="old-price">￥{{item.mktprice}}</text>
  </view>
  <navigator class='a'>
  <label class='ti1'>可使用优惠券</label>
  </navigator>
  </block>
  <block wx:else>
  <navigator class='a'>
  <label class='ti'>对不起该商品已下架</label>
  </navigator>
  </block>

  </view>
 </view>
 </view>
 </view>
<view class="del" catchtap="del" data-index="{{index}}" data-productid="{{item.product_id}}" data-goodsid="{{item.goods_id}}">删除</view>
</view>

 data: {
 startX: 0, //开始坐标
 startY: 0
 },
 touchstart: function(e) {
 //开始触摸时 重置所有删除
 this.data.items.forEach(function(v, i) {
 if (v.isTouchMove) //只操作为true的
 v.isTouchMove = false;
 })
 this.setData({
 startX: e.changedTouches[0].clientX,
 startY: e.changedTouches[0].clientY,
 items: this.data.items
 })
 },
 //滑动事件处理
 touchmove: function(e) {
 var that = this,
 index = e.currentTarget.dataset.index, //当前索引
 startX = that.data.startX, //开始X坐标
 startY = that.data.startY, //开始Y坐标
 touchMoveX = e.changedTouches[0].clientX, //滑动变化坐标
 touchMoveY = e.changedTouches[0].clientY, //滑动变化坐标
 //获取滑动角度
 angle = that.angle({
 X: startX,
 Y: startY
 }, {
 X: touchMoveX,
 Y: touchMoveY
 });
 that.data.items.forEach(function(v, i) {
 v.isTouchMove = false
 //滑动超过30度角 return
 if (Math.abs(angle) > 30) return;
 if (i == index) {
 if (touchMoveX > startX) //右滑
  v.isTouchMove = false
 else //左滑
  v.isTouchMove = true
 }
 })
 //更新数据
 that.setData({
 items: that.data.items
 })
 },

 /**
 * 计算滑动角度
 * @param {Object} start 起点坐标
 * @param {Object} end 终点坐标
 */
 angle: function(start, end) {
 var _X = end.X - start.X,
 _Y = end.Y - start.Y
 //返回角度 /Math.atan()返回数字的反正切值
 return 360 * Math.atan(_Y / _X) / (2 * Math.PI);
 },

.touch-item {
 background-color: #fff;
 margin-top: 20rpx;
 display: flex;
 justify-content: space-between;
 width: 100%;
 overflow: hidden;
 box-sizing: border-box;
}

.content {
 width: 100%;
 -webkit-transition: all 0.4s;
 transition: all 0.4s;
 -webkit-transform: translateX(180rpx);
 transform: translateX(180rpx);
 margin-left: -180rpx;
}

.touch-move-active .content, .touch-move-active .del {
 -webkit-transform: translateX(0);
 transform: translateX(0);
}

.com {
 padding: 25rpx;
 height: 210rpx;
}

.tp {
 background-color: white;
 float: left;
}

.img {
 width: 210rpx;
 height: 210rpx;
 display: inline-block;
 vertical-align: middle;
 border-radius: 15rpx;
}

.txt {
 width: 420rpx;
 margin-left: 270rpx;
 position: relative;
}

.txt .tit {
 font-size: 28rpx;
 display: -webkit-box;
 -webkit-box-orient: vertical;
 -webkit-line-clamp: 2;
 overflow: hidden;
}

.txt .bot {
 width: 100%;
 font-size: 24rpx;
 margin-top: 20rpx;
}

.ti1 {
 margin-top: 15rpx;
 font-size: 23rpx;
 background-color: #fce64c;
 padding: 10rpx;
 display: inline-block;
}

.ti {
 margin-top: 35rpx;
 font-size: 28rpx;
 display: inline-block;
 color: #a2a2a2;
}

.del {
 background-color: red;
 width: 180rpx;
 display: flex;
 flex-direction: column;
 align-items: center;
 justify-content: center;
 color: #fff;
 -webkit-transform: translateX(180rpx);
 transform: translateX(180rpx);
 -webkit-transition: all 0.4s;
 transition: all 0.4s;
}

.new-price {
 font-weight: 600;
 color: #ff503c;
 font-size: 35rpx;
}

.old-price {
 margin-left: 30rpx;
 text-decoration: line-through;
 font-size: 28rpx;
 color: #b1b1b1;
}