嵌套的UpdatePanel

    <form id="form1" runat="server">
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>

    <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
            <%= DateTime.Now %>
            <asp:UpdatePanel ID="UpdatePanel2" runat="server">
                <ContentTemplate>
                    <%= DateTime.Now %>
                    <asp:Button ID="Button1" runat="server" Text="Button" />
                </ContentTemplate>
            </asp:UpdatePanel>
        </ContentTemplate>
    </asp:UpdatePanel>

    </form>

点击Button1按钮，只有UpdatePanel2里面的时间会更新，而UpdatePanel1中的时间不会更新，当前套UpdatePanel时，里面的UpdatePanel的控件回发不会引起外面一层的UpdatePanel更新