Combobox don't displays items in updatepanel

[Hugo]

Hi,
I have a page, that has 2 update panels, first with toolbar and second with tabstrip and multipage, from 1 item of my toolbar a usercontrol is loaded in a dinamically created pageview, this usercontrol has a telerik:combobox and a button. When I click the combobox nothing happens, the combobox don't displays items. The items are static, defined in the sme control.

I paste part of the codes.

Default.aspx (parent page)
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
                    <ContentTemplate>
                        <telerik:RadAjaxPanel ID="ContentPanel" runat="server" Height="100%" Width="100%" EnableAJAX="true" LoadingPanelID="ContentLoading">
                        <telerik:RadTabStrip ID="ContentTabStrip" runat="server" 
                            CausesValidation="False" MultiPageID="ContentMultiPage" SelectedIndex="0" 
                             Width="100%" ShowBaseLine="True">
                            <Tabs>
                            </Tabs>
                        </telerik:RadTabStrip>
                        <telerik:RadMultiPage ID="ContentMultiPage" runat="server" SelectedIndex="0" Height="100%" Width="100%" ScrollBars="Hidden">
                        </telerik:RadMultiPage>
                        </telerik:RadAjaxPanel>
                    </ContentTemplate>
                    <Triggers>
                        <asp:AsyncPostBackTrigger ControlID="MenuBar" />
                    </Triggers>
                </asp:UpdatePanel>

ConfigTemplate.ascx
<%@ Control Language="VB" AutoEventWireup="false" CodeFile="ConfigTemplate.ascx.vb" Inherits="ConfigTemplate" %>
<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
<div style="padding: 5px; font-family: Caibri, Arial; font-size: 9pt; border: 1px solid gray; border-top-width: 0px;">
    Plantillas:
    <telerik:RadComboBox ID="RadComboBox1" runat="server" 
        LoadingMessage="Cargando..." Sort="Ascending">
   <Items>
       <telerik:RadComboBoxItem runat="server" Text="RadComboBoxItem1"  />
       <telerik:RadComboBoxItem runat="server" Text="RadComboBoxItem2" />
       <telerik:RadComboBoxItem runat="server" Text="RadComboBoxItem3" />
   </Items>
</telerik:RadComboBox>
    <br /><br />

    <div id="Resultado" runat="server"></div>
    <telerik:RadButton ID="TemplatesCerrar" EnableAjaxSkinRendering="true" runat="server" Text="Cerrar"></telerik:RadButton>
    Se aplicara instantaneamente.
</div>

Is some way to make it work? I'm using 2011 Q2 version of AJAX RadControls

[Ivana]

Hi Hugo,

I have noticed that you are making a conditional post back to the server which is initiated by the control with ID="MenuBar". Make sure you have such control on the page.

Also having RadAjaxPanel inside an UpdatePanel is really not a good approach, since both of them are doing almost the same. For more complex scenarios, we advice to use a RadAjaxManager, about which information could be found here: RadAjaxManager.

For more information about using a RadAjax in UserControls scenarios, you could refer to the following help article on our website: RadAjax and WebUserControls.

Hope this helps.

Greetings,
Ivana
the Telerik team