"The Controls collection cannot be modified because the control contains code blocks"

First, start the code block with <%# instead of <%= :

<head id="head1" runat="server">
  <title>My Page</title>
  <link href="css/common.css" rel="stylesheet" type="text/css" />
  <script type="text/javascript" src="<%# ResolveUrl("~/javascript/leesUtils.js") %>"></script>
</head>

This changes the code block from a Response.Write code block to a databinding expression.
Since <%# ... %> databinding expressions aren't code blocks, the CLR won't complain. Then in the code for the master page, you'd add the following:

protected void Page_Load(object sender, EventArgs e)
{
  Page.Header.DataBind();    
}

I just ran into this problem as well but found another solution.

I found that wrapping the code blocks with a asp:PlaceHolder-tag solves the problem.

<asp:PlaceHolder runat="server">
  <meta name="ROBOTS" content="<%= this.ViewData["RobotsMeta"] %>" />
</asp:PlaceHolder>

(The CMS I'm using is inserting into the head-section from some code behind which restricted me from adding custom control blocks with various information like meta-tags etc so this is the only way it works for me.)


I can confirm that moving the javascript with <% %> tags from the head to the form tag fixes this error

http://italez.wordpress.com/2010/06/22/ajaxcontroltoolkit-calendarextender-e-strana-eccezione/

Tags:

C#

Asp.Net

User Controls

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