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='../../images/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();
  })
 }

})