<asp:Button点击查询后，调用js中函数展现加载圈

<div>
<div id='paneloading' style='display:none;position:fixed;top:0px;left:0px;z-index:999999;width:100%;height:100%;background-color:lightgrey;filter:alpha(opacity=70);opacity:0.7;'>
<div style='z-index:9999999;width:300px;height:150px;position:fixed;top:50%;left:50%; margin-left:-150px;margin-top:-75px;filter:alpha(opacity=100);opacity:1;'>
</div>
<div style='text-align:center' id='loadingpicture'>
<img src="http://img.blog.csdn.net/20171012174412760?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvc2luYXRfMTY5OTg5NDU=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" />
</div>
<div id='loadingcontent' style='text-align:center;height:40px;'> 正在加载... </div>
</div>
</div>

<asp:Button ID="Search_list" runat="server" Text="查询" Width="60px" OnClick="Search_list_Click"  onClientClick="ShowLoading()"/>

//注：onClientClick调用js中的函数，OnClick调用后台总的函数。

<script type="text/javascript">
//点击查询后展现加载图片
function ShowLoading() {
$("#paneloading").show();
}
</script>

//注:借鉴自http://blog.csdn.net/sinat_16998945/article/details/61923123