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

复制代码 代码如下:

<asp:ScriptManager ID="ScriptManager1" runat="server">

</asp:ScriptManager> //必须有且一定在updatepanel前面

<asp:UpdatePanel ID="UpdatePanel1" runat="server">

<ContentTemplate>

<% =DateTime.Now.ToString()%>

</ContentTemplate>

<Triggers>

<asp:PostBackTrigger ControlID="btn" />

<asp:AsyncPostBackTrigger ControlID="btn2" EventName="click" />

</Triggers>

</asp:UpdatePanel>

<asp:Button runat="server" Text="刷新1" id="btn"/>

<asp:Button runat="server" Text="刷新2" id="btn2" />

<% =DateTime.Now.ToString()%>