Strange Update Panel Error in Resource File

[John Kotuby]

Hi all,

I have successfully created a well functioning stand-alone ASPX page written
in VB using VS 2008 and the 3.5 framework. It uses an UpdatePanel with 5
controls inside the ContentTemplate and works as expected.

However. when I place essentailly the same code in the Content area of a
Master Page I have problems with it. There is no ScriptManager on the Master
Page and therefore I should not require a ScriptManagerProxy.


<asp:ScriptManager ID="ScriptManager1" runat="server" >
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"
ChildrenAsTriggers="false" >
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnPostUpd" />
</Triggers>
<ContentTemplate>...

The defined Trigger is an ASP Button outside of the UpdatePanel region whose
Click event is called by various JavaScript functions that I created to do
some setup work before submitting the Callback, such as populating the
values of hidden fields which I use during the Callback processing to
determine the proper serverside functions to run, etc. These Javascript
functions are the same ones used in the stand-alone version of the page...
which works just fine.


Running in the debugger I get ...

htmlfile:Unknown runtime error

The callstack is pointing to Sys$WebForms$PageRequestManager$_updatePanel.

The line of code highlighted is:

// Update the region with the new UpdatePanel content
updatePanelElement.innerHTML = rendering;

Which is in a ScriptResource.axd with a long querystring
(?d=C7zdOE..........)

When I Break and place my cursor over the highlighted code I see what looks
like valid InnerHtml as below.

rendering = "
<table id="tblListLocator" align="center" width="98%"
cellpadding="0px" cellspacing="0"
border="1" bordercolor="silver">
<tr>
<td align="center" colspan="2">
<div style="position:absolut...

Has anyone seen anything like this before or have some idea why it might be
occurring?
So far I am stumped by this one.

Thanks for any input.

 

[John Kotuby]

Hi all,
Well thankfully I discovered the nature of the problem. I will recount the
error cause and fix here, in case anybody else has a similar problem.

It was indeed related to my porting code from a stand-alone page to a
content page. I was replacing an exisitng set of controls within the Content
area with the ones contained in the UpdatePanel. I wanted to leave some
controls at the very top of the content area and replace others below them.
The controls that were to remain resided in a table structure used for
layout.

I mistakenly placed the script manager and update panel and its content
template after a </TR> and before the closing </TABLE> element resulting in
something like what I will display below.

<TABLE>
<TR><TD>
.... exisitng controls ...
</TD></TR>

<asp:ScriptManager ID="ScriptManager1" runat="server" >
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"
ChildrenAsTriggers="false" >
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnPostUpd" />
</Triggers>
<ContentTemplate>
.... new controls within a table layout ...
</ContentTemplate>

</TABLE>

For some reason Intellisense did not balk at this mistake, even though I had
another Table layout within the ContentTemplate area. So I missed the error.
Apparently Intellisense does not consider placing an UpdatePanel between the
last </TR> and the closing </TABLE> a problem.

However, as soon as I moved the closing </TABLE> tag above the ScriptManager
everything started working correctly.

Thanks to anyone who looked at this post and gave it some thought.
Hopefully my solution will be helpful to the community.

 

[Julien Hoffmann]

Hi all,
Me too I thought I could give out my solution to a similar problem ; hopefully it will help.
Long story made short :
On a VB.NET 3.5 + AJAX web site, I wanted my visitors to be able to navigate inside one page unsing anchors.
Anchors inside content rendered by a listview inside an update panel are ok, but....believe it or not, the "top" anchor, referring to the top of page was causing the "unknown error" !
Anchor was <a name="top" /> and was located outside the update panel, under the opening form tag and before the scriptmanager tag.
Got rid of it and all worked fine again. Don't ask why...
Happy programming.
JH