微信小程序列表项滑动显示删除按钮

微信小程序并没有提供列表控件，所以也没有iOS上惯用的列表项左滑删除的功能，SO只能自己干了。

原理很简单，用2个层，上面的层显示正常的内容，下面的层显示一个删除按钮，就是记录手指滑动的距离，动态的来移动上层元素，当然上层用绝对定位。

wxml：

<view class="container">
  <view class="record-box" data-datetime="{{record.datetime}}" wx:for="{{detailList}}" wx:for-item="record">
    <view class="record" style="left:{{record.offsetX}}px" bindtouchstart="recordStart" catchtouchmove="recordMove" bindtouchend="recordEnd">
      <view class="left">
        <view>{{record.type}} {{record.count+record.unit}}</view>
        <view class="summary">{{record.remark}}</view>
      </view>
      <view class="right">
        {{record.datetime}}
      </view>
    </view>
    <view class="delete-box">
      <view>删除</view>
    </view>
  </view>
</view>

　　wxss：

@import "../common/weui.wxss";

.container {
  box-sizing: border-box;
  padding: 0 0 0 0;
}



.record {
  display: flex;
  flex-direction: row;
  align-items: center;
  100%;
    height: 120rpx;
  position: absolute;
  justify-content: space-between;
  background-color: #fff;
}

.record .right{
  margin-right: 30rpx;
     color: #888888;
}
.record .left{
  margin-left: 30rpx;
    display: flex;
    flex-direction: column;
  justify-content: space-between;
}

.record .left .summary{
    color: #aaa;
  font-size: 30rpx;
  line-height: 30rpx;

}

.record-box{
  height: 120rpx;
   100%;
  border-bottom: 1rpx solid #ddd;
  background-color: #fff;
}

.delete-box{
  background-color: #e64340;
  color: #ffffff;
  float: right;
  height: 100%;
   80px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.record-box:last-child {
  border-bottom: 0;
}

.record .r-item {
  
}

　　

var detailList = [
    { datetime: '2017-01-01 17:00', count: 100, unit: 'ml', type: '开水', remark: '哈哈哈哈' },
    { datetime: '2017-01-01 17:01', count: 100, unit: 'ml', type: '开水' },
    { datetime: '2017-01-01 17:02', count: 100, unit: 'ml', type: '开水' }
];
var recordStartX = 0;
var currentOffsetX = 0;
Page(
    {
        data: {
            detailList: detailList
        }
        ,
        recordStart: function (e) {
            recordStartX = e.touches[0].clientX;
            currentOffsetX = this.data.detailList[0].offsetX;
            console.log('start x ', recordStartX);
        }
        ,
        recordMove: function (e) {
            var detailList = this.data.detailList;
            var item = detailList[0];
            var x = e.touches[0].clientX;
            var mx = recordStartX - x;
            console.log('move x ', mx);

            var result = currentOffsetX - mx;
            if (result >= -80 && result <= 0) {
                item.offsetX = result;
            }
            this.setData({
                detailList: detailList
            });
        }
        ,
        recordEnd: function (e) {
            var detailList = this.data.detailList;
            var item = detailList[0];
            console.log('end x ', item.offsetX);

            if (item.offsetX < -40) {
                item.offsetX = -80;

            } else {
                item.offsetX = 0;

            }
            this.setData({
                detailList: detailList
            });
        }

    }
);