Controls Collection Cannot Be Modified because of Code Blocks Error Occurs
Environment
| Product | Progress® Telerik® UI for ASP.NET AJAX |
Description
When working with Telerik UI for ASP.NET AJAX, I get an error that the controls collection cannot be modified because the control contains code blocks.
Error Message
The Controls collection cannot be modified because the control contains code blocks
Cause
The possible cause for this issues is that the code block is inside the head tag, for example:
<head id="Head1" runat="server">
<script type="text/javascript">
var grid = $find('<%= RadGrid1.ClientID %>');
...
</script>
</head>
<body>
...
</body>
Solution
To solve this issue, move the code block (<% ... %>) outside the head tag:
<head id="Head2" runat="server">
<telerik:RadCodeBlock id="RadCodeBlock1" runat="server">
<script type="text/javascript">
var grid = $find('<%= RadGrid1.ClientID %>');
...
</script>
</telerik:RadCodeBlock>
</head>
<body>
...
</body>
or
<head id="Head3" runat="server">
</head>
<body>
<telerik:RadCodeBlock id="RadCodeBlock1" runat="server">
<script type="text/javascript">
var grid = $find('<%= RadGrid1.ClientID %>');
...
</script>
</telerik:RadCodeBlock>
</body>