微信小程序实现左滑修改、删除功能

<view class="offer-item" wx:for-items='{{offerList}}'>
 <!--这里绑定了刚才说的3个函数分别为 touchS，touchM touchE-->
 <!--这里注意这个 style="{{item.txtStyle}}" ，这是我们一会再js中 将要设置的样式 -->
 <view style="{{item.txtStyle}}">
  <view class="offer-item-top fl clearfix" bindtouchstart="touchS" bindtouchmove="touchM" bindtouchend="touchE" data-index="{{index}}">
  <navigator bindtap='navigatorTo' data-index="{{item.id}}">
   <view class='content'>
   <view class='title clearfix'>
    <view class='fl'>
    {{item.title}}党建项目报价表
    </view>
    <image src='../../images/right.png' class='fr'></image>
   </view>
   <view class='note clearfix'>
    <view class='price fl'>
    {{item.create_time}}
    </view>
   </view>
   </view>
  </navigator>
  </view>

  <!--这里是左滑按钮部分----start-->
  <view bindtap="delItem" class='posit fr isMove' hidden='{{!item.isMove}}'>
   <view class="ref" data-offerid="{{item.id}}" data-index="{{item.id}}" catchtap="ref">
   <image src='../../images/ref.png'></image>
   </view>
   <view class="del" data-offerid="{{item.id}}" data-index="{{item.id}}" catchtap="del">
   <image src='../../imageshttps://img.qb5200.com/download-x/default.png'></image>
   </view>
  </view>
  <!--这里是左滑按钮部分----end-->
 </view>
</view>

.offer-item {
 height: 150rpx;
 width: 100vw;
 overflow-x: hidden;
 border-bottom: 1px solid #f0f0f0;
}

.offer-item>view {
 position: absolute;
 /* width: calc(100% + 200rpx); */
 height: 150rpx; 
}

.offer-item .offer-item-top {
 height: 100%;
}

.offer-item .offer-item-top navigator {
 display: inline-block;
 width: 100vw; 
 height: 100%;
}

.offer-item .content {
 padding: 35rpx 30rpx;
 position: relative;
 height: calc(100% - 70rpx);
}

.offer-item .title .fl {
 display: inline-block;
 width: 78%;
 overflow: hidden;
 text-overflow: ellipsis;
 white-space: nowrap;
 font-size: 30rpx;
 color: #333;
}

.offer-item .title .fr {
 display: inline-block;
 width: 20rpx;
 height: 26rpx;
 margin-top: 5rpx;
}

.offer-item .note {
 position: absolute;
 left: 30rpx;
 bottom: 35rpx;
 width: calc(100vw - 60rpx);
 font-size: 24rpx;
 color: #999;
}

.offer-item .posit {
 width: 200rpx;
 height: 150rpx;
 line-height: 150rpx;
 text-align: center;
 display: none
}

.posit.isMove {
 display: inline-block;
 position: absolute;
}

.posit.isMove[hidden] {
 display: none
}

.offer-item .posit>view {
 display: inline-block;
 width: 100rpx;
}

.offer-item .posit>view:first-of-type {
 background-color: #FED847;
}

.offer-item .posit>view:last-of-type {
 background-color: #C71B1B;
}

.offer-item .posit image {
 display: inline-block;
 width: 36rpx;
 height: 36rpx;
}

let len = 0;   // 初次加载长度
let hadLastPage = false; // 判断是否到最后一页

var initdata = function (that) {
 var list = that.data.offerList
 for (var i = 0; i < list.length; i++) {
 list[i].txtStyle = "";
 list[i].isMove = false;
 }
 that.setData({ 
 offerList: list
 })
}

Page({
 data: {
 offerList: [

 ],
 delBtnWidth: 100,  // 删除按钮宽度单位（rpx）
 },


 // 手指刚放到屏幕触发
 touchS: function (e) {
 console.log("touchS" + e);
 // initdata(this);
 // 判断是否只有一个触摸点
 if (e.touches.length == 1) {
  this.setData({
  // 记录触摸起始位置的X坐标
  startX: e.touches[0].clientX
  });
 };
 return false;
 },

 // 触摸时触发，手指在屏幕上每移动一次，触发一次
 touchM: function (e) {
 var that = this;
 initdata(that);
 if (e.touches.length == 1) {
  // 记录触摸点位置的X坐标
  var moveX = e.touches[0].clientX;
  // 计算手指起始点的X坐标与当前触摸点的X坐标的差值
  var disX = that.data.startX - moveX;
  // delBtnWidth 为右侧按钮区域的宽度
  var delBtnWidth = that.data.delBtnWidth;
  var txtStyle = "";
  if (disX == 0 || disX < 0) {  // 如果移动距离小于等于0，文本层位置不变
  txtStyle = "left:0px";
  } else if (disX > 0) {   // 移动距离大于0，文本层left值等于手指移动距离
  txtStyle = "left:-" + disX + "px";
  if (disX >= delBtnWidth) {
   // 控制手指移动距离最大值为删除按钮的宽度
   txtStyle = "left:-" + delBtnWidth + "px";
  }
  }
  // 获取手指触摸的是哪一个item
  var index = e.currentTarget.dataset.index;
  var list = that.data.offerList;
  // 将拼接好的样式设置到当前item中
  list[index].txtStyle = txtStyle;

  list[index].isMove = true;
  // 更新列表的状态
  this.setData({
  offerList: list
  });
 }
 },
 touchE: function (e) {
 console.log( e);
 var that = this
 if (e.changedTouches.length == 1) {
  // 手指移动结束后触摸点位置的X坐标
  var endX = e.changedTouches[0].clientX;
  // 触摸开始与结束，手指移动的距离
  var disX = that.data.startX - endX;
  var delBtnWidth = that.data.delBtnWidth;
  // 如果距离小于删除按钮的1/2，不显示删除按钮
  var txtStyle = disX > delBtnWidth / 2 ? "left:-" + delBtnWidth + "px" : "left:0px";
  // 获取手指触摸的是哪一项
  var index = e.currentTarget.dataset.index;
  var list = that.data.offerList;
  list[index].txtStyle = txtStyle;
  // 更新列表的状态
  that.setData({
  offerList: list
  });
 }
 },

 /**
 * 
 */
 navigatorTo: function (event) {

 },

 /**
 * 删除操作
 */
 del: function (e) {
 var that = this;
 var data = {
  id: e.currentTarget.dataset.index
 };
 wx.showModal({
  title: '',
  content: '确定选择删除么？',
  confirmColor: '#C71B1B',
  cancelColor: '#666666',
  success: function (res) {
  if (res.confirm) {
   utils.requestFun("接口url", data, 'POST', function (msg) {
   console.log(msg)

   wx.showToast({
    title: '删除成功',
    icon: 'success',
    duration: 1500
   })
   var lists = that.data.offerList;
   var list1 = [];
   for (let i = 0; i < lists.length; i++) {
    if (lists[i].id != e.currentTarget.dataset.index) {
    list1.push(lists[i])
    }
   }
   len--;
   that.setData({
    offerList: list1
   })
   })
  } else if (res.cancel) {

  }
  }
 })
 },

 /**
 * 修改操作
 */
 ref: function (e) {
 wx.navigateTo({
  url: '修改页面路径?id=' + e.currentTarget.dataset.index,
 })
 },

 /**
 * 生命周期函数--监听页面加载
 */
 onLoad: function (options) {
 page = 0;
 this.loadList();
 },


 /**
 * 生命周期函数--监听页面初次渲染完成
 */
 onReady: function () {

 },

 /**
 * 生命周期函数--监听页面显示
 */
 onShow: function () {

 },

 /**
 * 生命周期函数--监听页面隐藏
 */
 onHide: function () {

 },

 /**
 * 生命周期函数--监听页面卸载
 */
 onUnload: function () {
  hadLastPage = false;
  len = 0; 
 },

 /**
 * 页面相关事件处理函数--监听用户下拉动作
 */
 onPullDownRefresh: function () {

 },

 /**
 * 页面上拉触底事件的处理函数
 */
 onReachBottom: function (event) {
 console.log("上拉事件")
 this.loadList();
 }, 

 /** 
 * 数据请求封装
 */
 loadList: function (event) {
 if (hadLastPage != false) {
  wx.showToast({
  title: '到底啦',
  });
  return;
 }
 var that = this;
 // 显示加载图标 
 wx.showLoading({
  title: '玩命加载中',
 })

 let data = {
  length: len,
  openId: 'openid'
 };
 utils.requestFun("接口url", data, 'POST', function (msg) {

  if (msg.data.length != 0) {
  var lists = that.data.offerList;
  for (let i = 0; i < msg.data.length; i++) {
   msg.data[i].isMove = false;
   lists.push(msg.data[i]);
  }

  // len 
  len = len + msg.data.length;

  // 设置数据 
  that.setData({
   offerList: lists
  })
  } else {
  hadLastPage = true;
  }
  wx.hideLoading();
 })
 }

})