"The Controls collection cannot be modified because the control contains code blocks"
- by Daniel P
I am trying to create a simple user control that is a slider. When I add a AjaxToolkit SliderExtender to the user control I get this (*&$#()@# error:
Server Error in '/' Application. The
Controls collection cannot be modified
because the control contains code
blocks (i.e. <% ... %). Description:
An unhandled exception occurred during
the execution of the current web
request. Please review the stack trace
for more information about the error
and where it originated in the code.
Exception Details:
System.Web.HttpException: The Controls
collection cannot be modified because
the control contains code blocks (i.e.
<% ... %).
Source Error:
An unhandled exception was generated
during the execution of the current
web request. Information regarding the
origin and location of the exception
can be identified using the exception
stack trace below.
Stack Trace:
[HttpException (0x80004005): The
Controls collection cannot be modified
because the control contains code
blocks (i.e. <% ... %).]
System.Web.UI.ControlCollection.Add(Control
child) +8677431
AjaxControlToolkit.ScriptObjectBuilder.RegisterCssReferences(Control
control) in
d:\E\AjaxTk-AjaxControlToolkit\Release\AjaxControlToolkit\ExtenderBase\ScriptObjectBuilder.cs:293
AjaxControlToolkit.ExtenderControlBase.OnLoad(EventArgs
e) in
d:\E\AjaxTk-AjaxControlToolkit\Release\AjaxControlToolkit\ExtenderBase\ExtenderControlBase.cs:306
System.Web.UI.Control.LoadRecursive()
+50 System.Web.UI.Control.LoadRecursive()
+141 System.Web.UI.Control.LoadRecursive()
+141 System.Web.UI.Control.LoadRecursive()
+141 System.Web.UI.Control.LoadRecursive()
+141 System.Web.UI.Control.LoadRecursive()
+141 System.Web.UI.Control.LoadRecursive()
+141 System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean
includeStagesAfterAsyncPoint) +627
Version Information: Microsoft .NET
Framework Version:2.0.50727.3074;
ASP.NET Version:2.0.50727.3074
I have tried putting a placeholder in the user control and adding the textbox and slider extender to the placeholder programmatically and I still get the error.
Here is the simple code:
<table cellpadding="0" cellspacing="0" style="width:100%">
<tbody>
<tr>
<td></td>
<td>
<asp:Label ID="lblMaxValue" runat="server" Text="Maximum" CssClass="float_right" />
<asp:Label ID="lblMinValue" runat="server" Text="Minimum" />
</td>
</tr>
<tr>
<td style="width:60%;">
<asp:CheckBox ID="chkOn" runat="server" /><asp:Label ID="lblPrefix" runat="server" />: <asp:Label ID="lblSliderValue" runat="server" /> <asp:Label ID="lblSuffix" runat="server" />
</td>
<td style="text-align:right;width:40%;">
<asp:TextBox ID="txtSlider" runat="server" Text="50" style="display:none;" />
<ajaxToolkit:SliderExtender ID="seSlider" runat="server"
BehaviorID="seSlider"
TargetControlID="txtSlider"
BoundControlID="lblSliderValue"
Orientation="Horizontal"
EnableHandleAnimation="true"
Length="200"
Minimum="0"
Maximum="100"
Steps="1" />
</td>
</tr>
</tbody>
What is the problem?
Thanks in advance.
Dan
