iscroll动态加载数据完美解决方法

<div id="wrapper" class="margin-b90">
    <div id="scroller">
      <div id="pullDown">
        <span class="pullDownLabel" style="text-align: center;">加载中...</span>
      </div>
      <div class="sps_itemBox ">
        <div class="list_show">
          <ul id="ulList"></ul>
        </div>
      </div>

      <div id="pullUp">
        <span class="pullUpLabel" style="text-align: center;">上拉加载...</span>
      </div>
    </div>
  </div>

// iScroll 滚动条/上拉刷新/下拉加载
var myScroll,
pullDownEl,
pullDownOffset,
pullUpEl,
pullUpOffset;

function loaded() {
pullDownEl = document.getElementById('pullDown');
pullDownOffset = pullDownEl.offsetHeight;
pullUpEl = document.getElementById('pullUp');
pullUpOffset = pullUpEl.offsetHeight;
myScroll = new iScroll('wrapper', {
useTransition: false,
topOffset: pullDownOffset,
btnOffset: pullUpOffset,
hideScrollbar: true,
fadeScrollbar: true,
onRefresh: function () {
if (pullDownEl.className.match('loading')) {
pullDownEl.className = '';
//pullDownEl.querySelector('.pullDownLabel').innerHTML = '下拉刷新...';
pullDownEl.querySelector('.pullDownLabel').innerHTML = '数据更新时间：' + updateDatetime;
} else if (pullUpEl.className.match('loading')) {
pullUpEl.className = '';
pullUpEl.querySelector('.pullUpLabel').innerHTML = '上拉加载...';
}
},
onScrollMove: function () {
if (this.y > 5 && !pullDownEl.className.match('flip')) {
pullDownEl.className = 'flip';
//pullDownEl.querySelector('.pullDownLabel').innerHTML = '释放刷新...';
pullDownEl.querySelector('.pullDownLabel').innerHTML = '数据更新时间：' + updateDatetime;
this.minScrollY = 0;
} else if (this.y < 5 && pullDownEl.className.match('flip')) {
pullDownEl.className = '';
//pullDownEl.querySelector('.pullDownLabel').innerHTML = '下拉刷新...';
pullDownEl.querySelector('.pullDownLabel').innerHTML = '数据更新时间：' + updateDatetime;
this.minScrollY = -pullDownOffset;
} else if (this.y < (this.maxScrollY - pullUpOffset - 40) && !pullUpEl.className.match('flip')) {
pullUpEl.className = 'flip';
pullUpEl.querySelector('.pullUpLabel').innerHTML = '释放加载...';
this.maxScrollY = this.maxScrollY - pullUpOffset;
}
//else if (this.y > (this.maxScrollY - pullUpOffset) && pullUpEl.className.match('flip')) {
// pullUpEl.className = '';
// pullUpEl.querySelector('.pullUpLabel').innerHTML = '上拉加载...';
// //this.maxScrollY = pullUpOffset;
//}
},
onScrollEnd: function () {
if (pullDownEl.className.match('flip')) {
pullDownEl.className = 'loading';
//pullDownEl.querySelector('.pullDownLabel').innerHTML = '数据刷新中...';
pullDownEl.querySelector('.pullDownLabel').innerHTML = '数据更新时间：' + updateDatetime;
myScroll.refresh();
} else if (pullUpEl.className.match('flip')) { 
pullUpEl.className = 'loading';
pullUpEl.querySelector('.pullUpLabel').innerHTML = '数据加载中...';
setTimeout(function () { myScroll.refresh(); }, 3000);

}
}
});
}
document.addEventListener('touchmove', function (e) { e.preventDefault(); }, false);
document.addEventListener('DOMContentLoaded', function () { setTimeout(loaded, 200); }, false);

/* iScroll */
#wrapper{width:100%; position:absolute; top:0; bottom:0; z-index:1; overflow:hidden;}
#scroller{
  width:100%; position:absolute; z-index:1;
  -webkit-touch-callout:none; -webkit-tap-highlight-color:rgba(0,0,0,0);
}
#pullDown,
#pullUp{padding:15px 0 15px 60px; font-size:14px; line-height:27px; color:#303030;}
#pullDown{background:url(../images/loadBottom.png) no-repeat 30px center; background-size:27px 27px;}
#pullUp{background:url(../images/loadTop.png) no-repeat 30px center; background-size:27px 27px;}
#pullDown.flip{background:url(../images/loadTop.png) no-repeat 30px center; background-size:27px 27px;}
#pullUp.flip{background:url(../images/loadBottom.png) no-repeat 30px center; background-size:27px 27px;}
#pullDown.loading,
#pullUp.loading{background:url(../images/loading.gif) no-repeat 30px center; background-size:25px 27px;}
/* iScroll end */