JavaScript实现移动端下拉刷新功能详解

<!DOCTYPE html>
<html lang="en">
 <head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no">
 </head>
 <body style="background-color: beige;">
  <div id="container" style="width:100%;border:solid 1px blue; transform:translate(0px,-61px)">
   <div style="height:50px; line-height:50px; text-align:center; width:100%; border:solid 1px red;">
    努力加载中...
   </div> 
   <div style="width:100%; line-height:30px;background-color:#F2F2F2; font-size:17px; font-family:'Adobe Garamond Pro'">
    下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新
    下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新
    下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉刷新下拉拉刷新下拉刷新
   </div>
  </div>
 </body>
</html>
<!--JQuery是那么的好用，这种情况下怎么能没有它呢！-->
<script type="text/javascript" src="http://libs.baidu.com/jquery/1.11.1/jquery.min.js"></script>

/*
 *obj--滑动对象
 *offset--滑动距离（当滑动距离大于等于offset时将调用callback）
 *callback--滑动完成后的回调函数
 */
 var slide = function (obj, offset, callback) {
  var start,
   end,
   isLock = false,//是否锁定整个操作
   isCanDo = false,//是否移动滑块
   isTouchPad = (/hp-tablet/gi).test(navigator.appVersion),
   hasTouch = 'ontouchstart' in window && !isTouchPad;
  //将对象转换为jquery的对象
  obj = $(obj);
  var objparent = obj.parent();
  /*操作方法*/
  var fn =
   {
    //移动容器
    translate: function (diff) {
     obj.css({
      "-webkit-transform": "translate(0," + diff + "px)",
      "transform": "translate(0," + diff + "px)"
     });
    },
    //设置效果时间
    setTranslition: function (time) {
     obj.css({
      "-webkit-transition": "all " + time + "s",
      "transition": "all " + time + "s"
     });
    },
    //返回到初始位置
    back: function () {
     fn.translate(0 - offset);
     //标识操作完成
     isLock = false;
    }
   };
  //滑动开始
  obj.bind("touchstart", function (e) {
   if (objparent.scrollTop() <= 0 && !isLock) {
    var even = typeof event == "undefined" ? e : event;
    //标识操作进行中
    isLock = true;
    isCanDo = true;
    //保存当前鼠标Y坐标
    start = hasTouch ? even.touches[0].pageY : even.pageY;
    //消除滑块动画时间
    fn.setTranslition(0);
   }
  });
  //滑动中
  obj.bind("touchmove", function (e) {
   if (objparent.scrollTop() <= 0 && isCanDo) {
    var even = typeof event == "undefined" ? e : event;
    //保存当前鼠标Y坐标
    end = hasTouch ? even.touches[0].pageY : even.pageY;
    if (start < end) {
     even.preventDefault();
     //消除滑块动画时间
     fn.setTranslition(0);
     //移动滑块
     fn.translate(end - start - offset);
    }
   }
  });
  //滑动结束
  obj.bind("touchend", function (e) {
   if (isCanDo) {
    isCanDo = false;
    //判断滑动距离是否大于等于指定值
    if (end - start >= offset) {
     //设置滑块回弹时间
     fn.setTranslition(1);
     //保留提示部分
     fn.translate(0);
     //执行回调函数
     if (typeof callback == "function") {
      callback.call(fn, e);
     }
    } else {
     //返回初始状态
     fn.back();
    }
   }
  });
 }

$(function () {
 slide("#container", 61, function (e) {
  var that = this;
  setTimeout(function () {
   that.back.call();
  }, 2000);
 });
});