小程序：下拉刷新，上拉加载

<view class=‘view-container‘>  
  <block wx:for=‘{{articles}}‘ wx:key=‘{{item.id}}‘>  
    <view class=‘articles-container‘>  
      <view class=‘info‘>  
        <image class=‘avatar‘ src=‘{{item.avatar}}‘></image>{{item.nickname}}  
        <text class=‘created-at‘>{{item.created_at}}</text>  
        <text class=‘category‘>{{item.category}}</text>  
      </view>  
    </view>  
  </block>  
  <view class=‘data-loading‘ hidden=‘{{hidden}}‘>  
    数据加载中...  
  </view>  
</view> 

.view-container {  
  background-color: #fff;  
}  
  
.data-loading {  
  height: 100rpx;  
  line-height: 100rpx;  
  background-color: #eee;  
  text-align: center;  
  font-size: 14px;  
}  
  
.articles-container {  
  border-bottom: 1px solid #eee;  
  margin: 30rpx 10rpx;  
  background-color: #eee;  
}  
  
.articles-container .info {  
  font-size: 12px;  
  margin: 20rpx 0rpx;  
  height: 100%;  
  display: inline-block;  
}  
  
.articles-container .info .avatar {  
  width: 60rpx;  
  height: 60rpx;  
  margin-right: 10rpx;  
  border-radius: 60rpx;  
  display: inline-block;  
  vertical-align: middle;  
}  
  
.articles-container .info .created-at {  
  margin: 0px 20rpx;  
  display: inline-block;  
  vertical-align: middle;  
}  
  
.articles-container .info .category {  
  color: #3399ea;  
  display: inline-block;  
  vertical-align: middle;  
}  

Page({

  data: {
    /** 
     * 需要访问的url 
     */
    urls: [
      ‘https://www.csdn.net/api/articles?type=more&category=home&shown_offset=0‘,
      ‘https://www.csdn.net/api/articles?type=new&category=arch‘,
      ‘https://www.csdn.net/api/articles?type=new&category=ai‘,
      ‘https://www.csdn.net/api/articles?type=new&category=newarticles‘
    ],
    /** 
     * 当前访问的url索引 
     */
    currentUrlIndex: 0,
    /** 
     * 获取到的文章 
     */
    articles: [],
    /** 
     * 控制上拉到底部时是否出现 "数据加载中..." 
     */
    hidden: true,
    /** 
     * 数据是否正在加载中，避免数据多次加载 
     */
    loadingData: false
  },

  onLoad: function (options) {
    this.loadData(false);
  },

  /** 
   * 加载数据 
   */
  loadData: function (tail, callback) {
    var that = this,
      urlIndex = that.data.currentUrlIndex;
    wx.request({
      url: that.data.urls[urlIndex],
      success: function (r) {
        var oldArticles = that.data.articles,
          newArticles = tail ? oldArticles.concat(r.data.articles) : r.data.articles;
        that.setData({
          articles: newArticles,
          currentUrlIndex: (urlIndex + 1) >= that.data.urls.length ? 0 : urlIndex + 1
        });
        if (callback) {
          callback();
        }
      },
      error: function (r) {
        console.info(‘error‘, r);
      },
      complete: function () { }
    });
  },

  /** 
   * 监听用户下拉动作 
   */
  onPullDownRefresh: function () {
    console.info(‘onPullDownRefresh‘);
    var loadingData = this.data.loadingData,
      that = this;
    if (loadingData) {
      return;
    }
    // 显示导航条加载动画  
    wx.showNavigationBarLoading();
    // 显示 loading 提示框,在 ios 系统下，会导致顶部的加载的三个点看不见  
    // wx.showLoading({  
    //   title: ‘数据加载中...‘,  
    // });  
    setTimeout(function () {
      that.loadData(false, () => {
        that.setData({
          loadingData: false
        });
        wx.stopPullDownRefresh();
        // wx.hideLoading();  
        wx.hideNavigationBarLoading();
        console.info(‘下拉数据加载完成.‘);
      });
    }, 1000);
  },

  /** 
   * 页面上拉触底事件的处理函数 
   */
  onReachBottom: function () {
    console.info(‘onReachBottom‘);
    var hidden = this.data.hidden,
      loadingData = this.data.loadingData,
      that = this;
    if (hidden) {
      this.setData({
        hidden: false
      });
      console.info(this.data.hidden);
    }
    if (loadingData) {
      return;
    }
    this.setData({
      loadingData: true
    });
    // 加载数据,模拟耗时操作  

    wx.showLoading({
      title: ‘数据加载中...‘,
    });

    setTimeout(function () {
      that.loadData(true, () => {
        that.setData({
          hidden: true,
          loadingData: false
        });
        wx.hideLoading();
      });
      console.info(‘上拉数据加载完成.‘);
    }, 1000);
  }
})