<!--WXML-->
<view id="box">
  <view class="list" wx:for="{{List}}" wx:key="List{{index}}">
    <image mode='aspectFill' class='list_img' src="{{item.imgUrl}}" ></image>
  </view>
</view>

  /* JS */
 // 封裝函數(shù)獲取ID為box的元素實際高度 
 getScrollHeight: function() {
  wx.createSelectorQuery().select('#box').boundingClientRect((rect) => {
   this.setData({
    scrollHeight: rect.height
   })
   console.log(this.data.scrollHeight)
  }).exec()
 },
 // 假設(shè)數(shù)據(jù)請求
 getDataList: function() {
  wx.request({
   url: 'test.php', //僅為示例，并非真實的接口地址
   success: function(res) {
   // 如果該元素下面的數(shù)據(jù)是動態(tài)獲取的，此方法在wx.request請求成功的回調(diào)函數(shù)中調(diào)用
    this.getScrollHeight()
   }
  })
 },

  //監(jiān)聽用戶滑動頁面事件
 onPageScroll: function(e) {
  
  if (e.scrollTop <= 0) {
   // 滾動到最頂部
   e.scrollTop = 0;
  } else if (e.scrollTop > this.data.scrollHeight) {
   // 滾動到最底部
   e.scrollTop = this.data.scrollHeight;
  }
  if (e.scrollTop > this.data.scrollTop || e.scrollTop >= this.data.scrollHeight) {
   //向下滾動 
   console.log('向下 ', this.data.scrollHeight)
  } else {
   //向上滾動 
   console.log('向上滾動 ', this.data.scrollHeight)
  }
  //給scrollTop重新賦值 
  this.setData({
   scrollTop: e.scrollTop
  })
 },

<scroll-view>
<view>Some of the words<view>
<view bindscroll="scroll" class="{{variable>200 ? 'class1' : 'class2'}}"</view>
</scroll-view>

//JS文件
 //滾動監(jiān)聽
 scroll: function (e) {
 this.setData({
  scrollTop:e.detail.scrollTop
 })
 }