Multiple Update Panels & Control Events

Thankfully i've been able to re-create this issue but i'm still not entirely sure why it happens as it does. I've created a page with two update panels, inside of each is a label and a button. Each label is set to the current date when the labels PreRender event fires. The first time this loads, each event fires at pretty much the same time. As expected if i press either of the buttons, both label PreRender events fire and update the corresponding label. However If i set the update mode to conditional on the updatepanel, both labels PreRender events fire but only the one which shares the update panel with the pressed button has the UI updated. In this trivial example thats not too much of a problem, however when I'm loading in a dataset in one of the panels, i dont want the data being re-loaded in each time a different update panel posts back. Thanks in advance, Matt Here's my trivial example HTML and C# c#

protected void Page_Load(object sender, EventArgs e) { }protected void Label1_PreRender(object sender, EventArgs e) { Label1.Text = DateTime.Now.ToString(); }protected void Label2_PreRender(object sender, EventArgs e) { Label2.Text = DateTime.Now.ToString(); }protected void Button2_Click(object sender, EventArgs e) { }protected void Button1_Click(object sender, EventArgs e) { }

<asp:ScriptManager ID="ScriptManager1" runat="server" /> <div> <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"> <ContentTemplate> <asp:Label ID="Label2" runat="server" OnPreRender="Label2_PreRender" Text="Label"></asp:Label> <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Submit 2" /> </ContentTemplate> </asp:UpdatePanel> </div> <asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional"> <ContentTemplate> <asp:Label ID="Label1" runat="server" OnPreRender="Label1_PreRender" Text="Label"></asp:Label> <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="Submit One" /> </ContentTemplate> </asp:UpdatePanel>

This is by design. When you have multiple UpdatePanels and each set to Conditional, UI updates only occur in that particular UpdatePanel. You can get more info about UpdatePanels in the docs:http://www.asp.net/AJAX/Documentation/Live/tutorials/UpdatePanelTutorials.aspx

For updating a label like you are, I would utilize PageMethods vs. and UpdatePanel anyway. You can mix the two technologies if you need to. Seehttp://encosia.com/2007/07/11/why-aspnet-ajax-updatepanels-are-dangerous for an excellent example and more information.

-Damien