浅谈小程序中下拉刷新和上拉加载功能怎么实现？（附代码）

<scroll-view class="scroll" scroll-y="{{true}}" upper-threshold="50"   
bindscrolltoupper="refresh"  style="height:700px">
  <l-loadmore show="{{upfresh}}" bindscrolltolower="getMore"  type="loading" loading-text="拼命刷新中">
</l-loadmore>

<l-loadmore show="{{downfresh}}" type="loading" loading-text="拼命加载中">
</l-loadmore>

//在小程序项目目录中执行下面的函数
npm install lin-ui

"usingComponents": {
    "l-loadmore":"/miniprogram_npm/lin-ui/loadmore/index",
    "l-loading":"/miniprogram_npm/lin-ui/loading/index",
  },

data: {
    downfresh:false,//底部加载展示控制
    upfresh:false//顶部加载展示控制
  },

//下拉刷新
refresh(){
    if(this.data.upfresh){
      console.log("还没刷新完成")
      return;
    }
    var that = this;
    this.setData({
      upfresh: true,
      // upfresh:false
    })
   
    setTimeout(function() {
      //updateData为自己的数据更新逻辑代码
      that.updateData(true,()=>{
        that.setData({
          upfresh: false,
      });
     })
      // wx.hideLoading();
    console.info('下拉刷新加载完成.');
  }, 500);
  },
    
      //更新数据
   updateData:function(tail, callback) {
  
    var that = this;
    console.log("updatedata-=-=seea"+that.data.searchValue)
    wx.request({
      url: app.gBaseUrl + 'compony-detail/page',
      method: 'GET',
      data: {
        page: 0,
        count: 20,
        componyname:that.data.searchValue
      },
      success: (res) => {
        this.setData({
          componys: res.data
        })
        if (callback) {
          callback();
        }
      }
    })
   },

 /**
   * 滑动到底部加载更多
   */
  getMore(){
    // downloadingData=this.data.downloadingData
    if(this.data.downfresh){
      console.log("还没加载完成")
      return;
    }
   var that = this;
    this.setData({
      downfresh: true,
      // upfresh:false
    })
   
    this.setData({
      downloadingData: true
      // upfresh:false
    })

    setTimeout(function() {
      that.loadData(true,()=>{
        that.setData({
        downfresh: false
      });
     })
      // wx.hideLoading();
    console.info('上拉数据加载完成.');
  }, 1000);
  },
    
      loadData: function(tail, callback) {
    var that = this;
    wx.request({
      url: app.gBaseUrl + 'compony-detail/page',
      method: 'GET',
      data: {
        page: that.data.componys.length,
        count: 20,
        componyname:that.data.searchValue
      },
      success: (res) => {
        // console.log(JSON.stringify(res.data))
        that.setData({
          componys: that.data.componys.concat(res.data),
        });
        if (callback) {
          callback();
        }
      }
    })
  },