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Placeholder is not updated by RadAjaxManager


<asp:Placeholder> and <asp:Literal> controls and their content do not get updated by RadAjaxManager.


RadAjaxManager looks for rendered content that it will wrap in an update panel. This means that the controls it AJAX-enables need to render on the page with the ID provided in the AjaxSettings.

Placeholders and LiteralControl instances do not render a wrapping element with their ID and so RadAjaxManager cannot get a proper handle on them. Sometimes this can also be true for user controls, depending on the concrete control.

You can get the same behavior for controls that initially had Visible="false" so they did not render.


Wrap the content in an element that will render an HTML element with its ID. For example, an <asp:Panel> or <asp:Label>.

<telerik:RadAjaxManager runat="server" ID="RadAjaxManager1">
        <telerik:AjaxSetting AjaxControlID="Button1">
                <telerik:AjaxUpdatedControl ControlID="Panel1" />
                <%--instead of ControlID="PlaceHolder1"--%>
<asp:Button Text="partial rendering" runat="server" ID="Button1" />
<asp:Panel runat="server" ID="Panel1">
    <asp:PlaceHolder runat="server" ID="PlaceHolder1"></asp:PlaceHolder>
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