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
    wx.getSystemInfo({
      success: function (res) {
        _this.setData({
          windowHeight: res.windowHeight
        })
        console.log("屏幕高度: " + res.windowHeight)
      }
    })
    //获取words
    wx.request({
      url: 'http://api.avatardata.cn/ChengYu/Search?key=77f072d28eb141c8b6dda145ca364b92&keyWord=好',
      complete: function (res) {
        if (res.data.reason == 'Succes') {
          _this.setData({
            words: res.data.result
          })
        }
      }
    })
  },
  scroll: function () {
    console.log("滑动了...")
  },
  lower: function () {
    var start = 0;
    start += 1;
    console.log("加载了...")
    var _this = this;
    wx.request({
      url: 'http://api.avatardata.cn/ChengYu/Search',
      data: {
        key: '77f072d28eb141c8b6dda145ca364b92', keyWord: '好', page: start
      },
      complete: function (res) {
        if (res.data.reason == 'Succes') {
          var words = _this.data.words.concat(res.data.result);
          _this.setData({
            words: words
          })
        }
      }
    })
  },
  upper: function () {
    console.log("下拉了....")
    //获取用户Y轴下拉的位移

    if (this.data.refreshing) return;
    this.setData({ refreshing: true });
    updateRefreshIcon.call(this);
    var _this = this;
    var i = Math.random() //获得0-1的随机数
    i = Math.ceil(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];
    wx.request({
      url: 'http://api.avatardata.cn/ChengYu/Search?key=77f072d28eb141c8b6dda145ca364b92&keyWord=' + word,

      complete: function (res) {
        if (res.data.reason == 'Succes') {
          setTimeout(function () {
            _this.setData({
              words: res.data.result
            })
          }, 2000)
        }
        setTimeout(function () {
          _this.setData({
            refreshing: false
          })
        }, 2500)
      }
    })
  },
  start: function (e) {
    var startPoint = e.touches[0]
    var clientY = startPoint.clientY;
    this.setData({
      clientY: clientY,
      refreshHeight: 0
    })
  },
  end: function (e) {
    var endPoint = e.changedTouches[0]
    var y = (endPoint.clientY - this.data.clientY) * 0.6;
    if (y > 50) {
      y = 50;
    }
    this.setData({
      refreshHeight: y
    })
  },
  move: function (e) {
    console.log("下拉滑动了...")
  }
})

/**
 * 旋转上拉加载图标
 */
function updateRefreshIcon() {
  var deg = 0;
  var _this = this;
  console.log('旋转开始了.....')
  var animation = wx.createAnimation({
    duration: 1000
  });

  var timer = setInterval(function () {
    if (!_this.data.refreshing)
      clearInterval(timer);
    animation.rotateZ(deg).step();//在Z轴旋转一个deg角度
    deg += 360;
    _this.setData({
      refreshAnimation: animation.export()
    })
  }, 1000);
}

2.index.wxml

<!--index.wxml-->
  <view class="refresh-block" style="height: {
  {refreshHeight}}px;" wx:if="{
  {refreshing}}">
    <image animation="{
  {refreshAnimation}}" src="../images/refresh.png"></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">{
  {item.name}}</view>
</block>
</scroll-view>

3.index.wxss

/**index.wxss**/
.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

我的博客:http://blog.csdn.net/qq_31383345

原文链接：https://blog.csdn.net/qq_31383345/article/details/53294184

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