ECSTORE导航吸顶功能

ecstore导航吸顶功能，在导航父元素中加入id，如：

<div id="mainNav1"></div>

在footer.html中添加以下js代码:

     <script type="text/javascript">function getTop(e)
     {
         var offset=e.offsetTop;
         if(e.offsetParent!=null) //只要还有父元素,也就是当前元素不是根节点就继续往上累计元素的高度
             offset+=getTop(e.offsetParent);
         return offset;
     }
     var myBlockTop = getTop(document.getElementById("mainNav1"));
     var oneDiv=document.getElementById("mainNav1");
     if(!!window.attachEvent)//ie浏览器下。
     {
         window.attachEvent('**croll',function(){
                         if(document.documentElement.scrollTop/* +  (document.body.clientHeight || window.innerHTML) */>= myBlockTop)
                         {oneDiv.style.position="fixed";oneDiv.style.top="0";oneDiv.style.left="0";oneDiv.style.display="block";oneDiv.style.zIndex="9999999999999";oneDiv.style.height="35px";oneDiv.innerHTML = document.getElementById("mainNav").innerHTML; }
                         else{oneDiv.style.display="none";}

         });
     }
     if(!!window.addEventListener)//非ie浏览器下
     {
         window.addEventListener("scroll",function(){//document.body.scrollTop可保证chrome的正常。
             if(document.documentElement.scrollTop/* +  (document.body.clientHeight || window.innerHTML) */>= myBlockTop||document.body.scrollTop>=myBlockTop)
             {oneDiv.style.position="fixed";oneDiv.style.top="0";oneDiv.style.width="100%";oneDiv.style.zIndex="9999999999999";oneDiv.style.display="block";oneDiv.style.height="35px";oneDiv.innerHTML =document.getElementById("mainNav").innerHTML;}
             else{oneDiv.style.display="none";}
         });
     }</script>

测试看看效果吧~