/*loading.js*/

 // 加载HTML图

 var _LoadingHtml = '<div id="loadingDiv" style="position:fixed;left: 0;top: 0;right: 0;bottom: 0;z-index: 99999;background-color: #fff;"><div style="position: fixed;top: 50%;left: 50%;transform: translate(-50%,-50%);"><img src="data:images/loading.gif" style="vertical-align: middle;width: 100px;">加载中。。。</div></div>';

 // 呈现loading效果

 document.write(_LoadingHtml);

 // 监听加载状态改变

 document.onreadystatechange = completeLoading;

 // 加载状态为complete时移除loading效果

 function completeLoading() {

     if (document.readyState == "complete") {

         var loadingMask = document.getElementById('loadingDiv');

         loadingMask.parentNode.removeChild(loadingMask);

     }

 }