最近公司要做报表，数据量比较大，页面加载往往加载需要一些时间,而这个时候用户(都是高层人物)如果只看到白屏的网页会以后IE死了，为了使自己的页面更加人性化,决定做一个 ”页面加载中“的效果，GOOGLE找了很多，发现大部分实现方式都是使用定时器,个人觉得定时器会造成一定程度上的假象，如定时器还没结束而页面已经加载完，或定时器已经结束而页面还没加载完。
本方法是用javascript来实现页面正在加载中的提示，先网页面里面写入一个层，显示加载框，然后等页面结束后在body的on
我的报表系统是多个页面的，所以写成一个公共类Common.cs，在类里加入如下函数：
代码
#region "页面加载中效果"
/// <summary>
/// 页面加载中效果
/// </summary>
public static void initJavascript()
{
HttpContext.Current.Response.Write(" <script language=JavaScript type=text/javascript>");
HttpContext.Current.Response.Write("var t_id = setInterval(animate,20);");
HttpContext.Current.Response.Write("var pos=0;var dir=2;var len=0;");
HttpContext.Current.Response.Write("function animate(){");
HttpContext.Current.Response.Write("var elem = document.getElementById(\'progress\');");
HttpContext.Current.Response.Write("if(elem != null) {");
HttpContext.Current.Response.Write("if (pos==0) len += dir;");
HttpContext.Current.Response.Write("if (len>32 || pos>79) pos += dir;");
HttpContext.Current.Response.Write("if (pos>79) len -= dir;");
HttpContext.Current.Response.Write(" if (pos>79 && len==0) pos=0;");
HttpContext.Current.Response.Write("elem.style.left = pos;");
HttpContext.Current.Response.Write("elem.style.width = len;");
HttpContext.Current.Response.Write("}}");
HttpContext.Current.Response.Write("function remove_loading() {");
HttpContext.Current.Response.Write(" this.clearInterval(t_id);");
HttpContext.Current.Response.Write("var targelem = document.getElementById(\'loader_container\');");
HttpContext.Current.Response.Write("targelem.style.display=\'none\';");
HttpContext.Current.Response.Write("targelem.style.visibility=\'hidden\';");
HttpContext.Current.Response.Write("}");
HttpContext.Current.Response.Write("</script>");
HttpContext.Current.Response.Write("<style>");
HttpContext.Current.Response.Write("#loader_container {text-align:center; position:absolute; top:40%; width:100%; left: 0;}");
HttpContext.Current.Response.Write("#loader {font-family:Tahoma, Helvetica, sans; font-size:11.5px; color:#000000; background-color:#FFFFFF; padding:10px 0 16px 0; margin:0 auto; display:block; width:130px; border:1px solid #5a667b; text-align:left; z-index:2;}");
HttpContext.Current.Response.Write("#progress {height:5px; font-size:1px; width:1px; position:relative; top:1px; left:0px; background-color:#8894a8;}");
HttpContext.Current.Response.Write("#loader_bg {background-color:#e4e7eb; position:relative; top:8px; left:8px; height:7px; width:113px; font-size:1px;}");
HttpContext.Current.Response.Write("</style>");
HttpContext.Current.Response.Write("<div id=loader_container>");
HttpContext.Current.Response.Write("<div id=loader>");
HttpContext.Current.Response.Write("<div align=center>页面正在加载中 ...</div>");
HttpContext.Current.Response.Write("<div id=loader_bg><div id=progress> </div></div>");
HttpContext.Current.Response.Write("</div></div>");
HttpContext.Current.Response.Flush();
}
#endregion
之后在需要调用的页面中在Page_Load()时间调用该方法：
Common.initJavascript();
并在每个页面body加载完毕后调用隐藏该div的事件
<body onload="remove_loading();">
OK!
