微信小程序 详解下拉加载与上拉刷新实现方法

onPullDownRefresh(){
　　console.log('--------下拉刷新-------')
　　wx.showNavigationBarLoading() //在标题栏中显示加载
 
　　wx.request({
     url: 'https://URL',
     data: {},
     method: 'GET',
     // OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, CONNECT
     // header: {}, // 设置请求的 header
     success: function(res){
      // success
     },
     fail: function() {
      // fail
     },
     complete: function() {
      // complete
      wx.hideNavigationBarLoading() //完成停止加载
      wx.stopPullDownRefresh() //停止下拉刷新
     }
  })       

<!--index.wxml-->
<view class="container" style="padding:0rpx">
 <!--垂直滚动，这里必须设置高度-->
  <scroll-view scroll-top="{{scrollTop}}" scroll-y="true" style="height:{{scrollHeight}}px;" 
    class="list" bindscrolltolower="bindDownLoad" bindscrolltoupper="topLoad" bindscroll="scroll">
    <view class="item" wx:for="{{list}}">
      <image class="img" src="http://9i0i.com/pic.php?p={{item.pic_url}}"></image>
      <view class="text">
        <text class="title">{{item.name}}</text>
        <text class="description">{{item.short_description}}</text>
      </view>
    </view>
  </scroll-view>
  <view class="body-view">
    <loading hidden="{{hidden}}" bindchange="loadingChange">
      加载中...
    </loading>
  </view>
</view>

var url = "http://www.imooc.com/course/ajaxlist";
var page =0;
var page_size = 5;
var sort = "last";
var is_easy = 0;
var lange_id = 0;
var pos_id = 0;
var unlearn = 0;


// 请求数据
var loadMore = function(that){
  that.setData({
    hidden:false
  });
  wx.request({
    url:url,
    data:{
      page : page,
      page_size : page_size,
      sort : sort,
      is_easy : is_easy,
      lange_id : lange_id,
      pos_id : pos_id,
      unlearn : unlearn
    },
    success:function(res){
      //console.info(that.data.list);
      var list = that.data.list;
      for(var i = 0; i < res.data.list.length; i++){
        list.push(res.data.list[i]);
      }
      that.setData({
        list : list
      });
      page ++;
      that.setData({
        hidden:true
      });
    }
  });
}
Page({
 data:{
  hidden:true,
  list:[],
  scrollTop : 0,
  scrollHeight:0
 },
 onLoad:function(){
  //  这里要注意，微信的scroll-view必须要设置高度才能监听滚动事件，所以，需要在页面的onLoad事件中给scroll-view的高度赋值
   var that = this;
   wx.getSystemInfo({
     success:function(res){
       that.setData({
         scrollHeight:res.windowHeight
       });
     }
   });
    loadMore(that);
 },
 //页面滑动到底部
 bindDownLoad:function(){  
   var that = this;
   loadMore(that);
   console.log("lower");
 },
 scroll:function(event){
  //该方法绑定了页面滚动时的事件，我这里记录了当前的position.y的值,为了请求数据之后把页面定位到这里来。
   this.setData({
     scrollTop : event.detail.scrollTop
   });
 },
 topLoad:function(event){
  //  该方法绑定了页面滑动到顶部的事件，然后做上拉刷新
   page = 0;
   this.setData({
     list : [],
     scrollTop : 0
   });
   loadMore(this);
   console.log("lower");
 }
})

/**index.wxss**/

.userinfo {
 display: flex;
 flex-direction: column;
 align-items: center;
}

.userinfo-avatar {
 width: 128rpx;
 height: 128rpx;
 margin: 20rpx;
 border-radius: 50%;
}

.userinfo-nickname {
 color: #aaa;
}

.usermotto {
 margin-top: 200px;
}

/**/

scroll-view {
 width: 100%;
}

.item {
 width: 90%;
 height: 300rpx;
 margin: 20rpx auto;
 background: brown;
 overflow: hidden;
}

.item .img {
 width: 430rpx;
 margin-right: 20rpx;
 float: left;
}

.title {
 font-size: 30rpx;
 display: block;
 margin: 30rpx auto;
}

.description {
 font-size: 26rpx;
 line-height: 15rpx;
}