详解微信小程序开发之下拉刷新 上拉加载

微信小程序中的下拉刷新,上拉加载的功能很常见,目前我知道的有两种可行的方法,一是scroll-view,二是整个页面刷新.今天说说第一种,自己造轮子,难免有些瑕疵,日后慢慢完善.

上gif:
原理: scroll-view中有监听滑动的方法,这个跟Android类似.其中用到了滑动到顶部,滑动到底部的方法.

1.下拉刷新,在滑动到顶部时,bindscrolltoupper被调用,根据自己的业务逻辑请求即可.我的demo只是随机换了个关键字.

2.上拉加载,在滑动到底部时,bindscrolltolower被调用,我这里是页数加一,根据自己的业务逻辑修改,然后将获取到的集合添加到scroll-view的数据集合里即可.

上代码:

1.index.js

//index.js 
//获取应用实例 
var app = getApp() 
Page({ 
 data: { 
 words: [], 
 windowHeight: 0,//获取屏幕高度 
 refreshHeight: 0,//获取高度 
 refreshing: false,//是否在刷新中 
 refreshAnimation: {}, //加载更多旋转动画数据 
 clientY: 0,//触摸时Y轴坐标 
 }, 
 onLoad: function () { 
 var _this = this; 
 //获取屏幕高度 
 wxgetSystemInfo({ 
  success: function (res) { 
  _thissetData({ 
   windowHeight: reswindowHeight 
  }) 
  consolelog("屏幕高度: " + reswindowHeight) 
  } 
 }) 
 //获取words 
 wxrequest({ 
  url: 'http://apiavatardatacn/ChengYu/Search?key=77f072d28eb141c8b6dda145ca364b92&keyWord=好', 
  complete: function (res) { 
  if (resdatareason == 'Succes') { 
   _thissetData({ 
   words: resdataresult 
   }) 
  } 
  } 
 }) 
 }, 
 scroll: function () { 
 consolelog("滑动了") 
 }, 
 lower: function () { 
 var start = 0; 
 start += 1; 
 consolelog("加载了") 
 var _this = this; 
 wxrequest({ 
  url: 'http://apiavatardatacn/ChengYu/Search', 
  data: { 
  key: '77f072d28eb141c8b6dda145ca364b92', keyWord: '好', page: start 
  }, 
  complete: function (res) { 
  if (resdatareason == 'Succes') { 
   var words = _thisdatawordsconcat(resdataresult); 
   _thissetData({ 
   words: words 
   }) 
  } 
  } 
 }) 
 }, 
 upper: function () { 
 consolelog("下拉了") 
 //获取用户Y轴下拉的位移 
 
 if (thisdatarefreshing) return; 
 thissetData({ refreshing: true }); 
 updateRefreshIconcall(this); 
 var _this = this; 
 var i = Mathrandom() //获得0-1的随机数 
 i = Mathceil(i * 10) //乘以10并向上去整 
 var words = ['龙', '一', '万', '千', '浩', '金', '得', '而', '可', '人']; 
 var word = words[i]; 
 wxrequest({ 
  url: 'http://apiavatardatacn/ChengYu/Search?key=77f072d28eb141c8b6dda145ca364b92&keyWord=' + word, 
 
  complete: function (res) { 
  if (resdatareason == 'Succes') { 
   setTimeout(function () { 
   _thissetData({ 
    words: resdataresult 
   }) 
   }, 2000) 
  } 
  setTimeout(function () { 
   _thissetData({ 
   refreshing: false 
   }) 
  }, 2500) 
  } 
 }) 
 }, 
 start: function (e) { 
 var startPoint = etouches[0] 
 var clientY = startPointclientY; 
 thissetData({ 
  clientY: clientY, 
  refreshHeight: 0 
 }) 
 }, 
 end: function (e) { 
 var endPoint = echangedTouches[0] 
 var y = (endPointclientY - thisdataclientY) * 6; 
 if (y > 50) { 
  y = 50; 
 } 
 thissetData({ 
  refreshHeight: y 
 }) 
 }, 
 move: function (e) { 
 consolelog("下拉滑动了") 
 } 
}) 
 
/** 
 * 旋转上拉加载图标 
 */ 
function updateRefreshIcon() { 
 var deg = 0; 
 var _this = this; 
 consolelog('旋转开始了') 
 var animation = wxcreateAnimation({ 
 duration: 1000 
 }); 
 
 var timer = setInterval(function () { 
 if (!_thisdatarefreshing) 
  clearInterval(timer); 
 animationrotateZ(deg)step();//在Z轴旋转一个deg角度 
 deg += 360; 
 _thissetData({ 
  refreshAnimation: animationexport() 
 }) 
 }, 1000); 
}

2.index.wxml

<!--indexwxml--> 
 <view class="refresh-block" style="height: {{refreshHeight}}px;" wx:if="{{refreshing}}"> 
 <image animation="{{refreshAnimation}}" src="/images/refreshpng"></image> 
 </view> 
<scroll-view scroll-y="true" style="height: {{windowHeight}}px;" bindscroll="scroll" bindscrolltolower="lower" bindscrolltoupper="upper" 
catchtouchmove="move" catchtouchstart="start" catchtouchend="end" 
> 
<block wx:for="{{words}}"> 
  <view class="item-style">{{itemname}}</view> 
</block> 
</scroll-view>

3.index.wxss

/**indexwxss**/ 
item-style{ 
 padding: 30rpx; 
 font-size: 40rpx; 
 text-align: center; 
 border-top: 2rpx solid #eee; 
} 
refresh-block { 
 padding: 15px; 
 text-align: center 
} 
refresh-block image { 
 width: 30px; 
 height: 30px; 
}

demo：下载地址
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