asyncpostbacktrigger(异步回调触发器):局部刷新,只刷新updatepanel内部的内容
postbacktrigger(普通回调触发器):全部刷新
<asp:Button runat="server" Text="刷新1" id="btn"/>
<asp:Button runat="server" Text="刷新2" id="btn2" />
<% =DateTime.Now.ToString()%>
原文:http://www.jb51.net/article/48395.htm