I have an issue when using the CalendarExtender control on an existing page. I'm pretty sure I know why it's happening, I just don't know how to fix it
My aspx page has the <head runat=server> which is required by the script manager to insert what I assume is the CSS references required by the calendar extender control.
The problem is, I get an exception stating:
The Controls collection cannot be modified because the control contains code blocks
We have javascript sitting in the head tag which uses class references to variables that point to aspx page names for example, so we don't have hardcoded page names all over the place. We also have an older implementation of "skinning" where the stylesheet is linked dynamically from a cookie variable, this is where the <%= code blocks are coming from and can't be removed.
Is there a solution to this? I understand the error but find it odd that code blocks are completely blocked in the head tag now
bump...... nobody?
I can't be the only one using code blocks within the <head> tag lol
Hi,
Can you provide a simple sample to illustrate the problem?
Sure, here's really simplified version but it demonstrates the error:
Default2.aspx<%@.PageLanguage="VB"AutoEventWireup="false"CodeFile="Default2.aspx.vb"Inherits="Default2" %>
<!DOCTYPEhtmlPUBLIC"-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><htmlxmlns="http://www.w3.org/1999/xhtml">
<headrunat="server">
<title>Untitled Page</title>
<scriptlanguage="javascript">
alert('<%=Default2.SomeVariable %>');</script>
</head><body>
<formid="form1"runat="server">
<div>
<asp:ScriptManagerID="ScriptManager1"runat="server">
</asp:ScriptManager>
</div>
<br/>
<asp:TextBoxID="TextBox1"runat="server"></asp:TextBox>
<ajaxToolkit:CalendarExtenderID="CalendarExtender1"runat="server"TargetControlID="TextBox1">
</ajaxToolkit:CalendarExtender>
</form></body>
</html>
In the code behind:
PublicShared SomeVariableAsString ="Hello"
I can see it now.
This is caused by how the Extender works internally. When an Extender is about to be rendered, it examine what css files are required and added it dynamically. So the exception is thrown.
To solve it, please don't use code block in html source directly. You may register it dynamically withRegisterClientScriptBlock method in code behind.
Raymond Wen - MSFT:
I can see it now.
This is caused by how the Extender works internally. When an Extender is about to be rendered, it examine what css files are required and added it dynamically. So the exception is thrown.
To solve it, please don't use code block in html source directly. You may register it dynamically withRegisterClientScriptBlock method in code behind.
Don't use code blocks? Put all my javascript in the code-behind?
Sorry but that's just ludicrous, there has to be another solution? I don't understand why the extender is not able to write a <link> tag in the head section just because there are code blocks present
Asp.net doesn't allow a container's control to be moved when the contaner has code blocks, this may not work reliably.
Another solution is you may move the code block out of the Header, and place it into the Form.
