JavaScript实现移动端下拉刷新效果详解

style type="text/css">
 #slideDown{margin-top: 0;width: 100%;}
   #slideDown1,#slideDown2{width: 100%;height: 70px;;background: #e9f4f7;display: none;}
   #slideDown1{height: 20px;}
   #slideDown1>p,#slideDown2>p{margin: 20px auto;text-align:center;font-size: 14px;color: #37bbf5;}
</style>


 <div id="content">
  <div id="slideDown">
   <div id="slideDown1">
    <p>松开刷新</p>
   </div>
   <div id="slideDown2">
    <p>正在刷新 ...</p>
   </div>
  </div>
  <div class="myContent">
   <ul>
    <li>item1 -- item1 -- item1</li>
    <li>item2 -- item2 -- item2</li>
    <li>item3 -- item3 -- item3</li>
    <li>item4 -- item4 -- item4</li>
    <li>item5 -- item5 -- item5</li>
    <li>item6 -- item6 -- item6</li>
    <li>item7 -- item7 -- item7</li>
   </ul>
  </div>
 </div>

<script type="text/javascript">
 //第一步：下拉过程
 function slideDownStep1(dist){ // dist 下滑的距离，用以拉长背景模拟拉伸效果
  var slideDown1 = document.getElementById("slideDown1"),
   slideDown2 = document.getElementById("slideDown2");
  slideDown2.style.display = "none";
  slideDown1.style.display = "block";
  slideDown1.style.height = (parseInt("20px") - dist) + "px";
 }
 //第二步：下拉，然后松开，
 function slideDownStep2(){ 
  var slideDown1 = document.getElementById("slideDown1"),
   slideDown2 = document.getElementById("slideDown2");
  slideDown1.style.display = "none";
  slideDown1.style.height = "20px";
  slideDown2.style.display = "block";
  //刷新数据
  //location.reload();
 }
 //第三步：刷新完成，回归之前状态
 function slideDownStep3(){ 
  var slideDown1 = document.getElementById("slideDown1"),
   slideDown2 = document.getElementById("slideDown2");
  slideDown1.style.display = "none";
  slideDown2.style.display = "none";
 }

 //下滑刷新调用
 k_touch("content","y");
 //contentId表示对其进行事件绑定，way==>x表示水平方向的操作，y表示竖直方向的操作
 function k_touch(contentId,way){ 
  var _start = 0,
   _end = 0,
   _content = document.getElementById(contentId);
  _content.addEventListener("touchstart",touchStart,false);
  _content.addEventListener("touchmove",touchMove,false);
  _content.addEventListener("touchend",touchEnd,false);
  function touchStart(event){ 
   //var touch = event.touches[0]; //这种获取也可以，但已不推荐使用

   var touch = event.targetTouches[0];
   if(way == "x"){ 
    _start = touch.pageX;
   }else{ 
    _start = touch.pageY;
   }
  }
  function touchMove(event){ 
   var touch = event.targetTouches[0];
   if(way == "x"){ 
    _end = (_start - touch.pageX);
   }else{ 
    _end = (_start - touch.pageY);
    //下滑才执行操作
    if(_end < 0){
     slideDownStep1(_end);
    }
   }

  }
  function touchEnd(event){ 
   if(_end >0){ 
    console.log("左滑或上滑 "+_end);
   }else{ 
    console.log("右滑或下滑"+_end);
    slideDownStep2();
    //刷新成功则
    //模拟刷新成功进入第三步
    setTimeout(function(){ 
     slideDownStep3();
    },2500);
   }
  }
 }
</script>