So I have several RadComboBoxes in my site that work perfectly fine in IE on the desktop, Chrome on the desktop, etc. ... but when I test them on an iOS device or Windows Phone (possibly Android, too ... haven't had a chance to test yet) they appear to render as native dropdown controls, but they don't have any data in them.

I'm defining RenderMode in the web.config as "Auto":

<add key="Telerik.Web.UI.RenderMode" value="Auto" />

Here's the definition of one of the comboboxes:

<telerik:RadComboBox ID="ddlUserGroups" Width="200px" MaxHeight="300px"
    DataValueField="UserPermissionGroupID" DataTextField="Name" runat="server"
    EnableEmbeddedSkins="false" AllowCustomText="false" MarkFirstMatch="true">
</telerik:RadComboBox>

I'm then databinding from code behind.

Any help would be appreciated.


George

Hello George,

Unfortunately, I was not able to reproduce the issue reported. I have prepared a sample page, which you can find attached.

While testing, I found out one major difference from your description - in the latest version Q1 2014 SP1 of Telerik UI for ASP.NET AJAX, when you set a global RenderMode "Auto" key in the web.config, RadComboBox is rendered in Lightweight render mode, not in Native render mode. This can be verified by the label just above the RadComboBox on the sample page. It displays the ResolvedRenderMode of the control.

Could you, please, specify the version you use? And in order to assist you in the most efficient way I would kindly suggest that you provide a very simplified runnable project (aspx page, codebehind and datasource) that demonstrates the behavior that you describe. Thus, we could test it locally and determine what might be causing the issue that you are experiencing.

Thank you in advance for your cooperation. 

Regards,
Dimitar
Telerik

Well, I can tell you that's not how it's behaving for me ... if I set RenderMode to Auto in the web.config, it renders on iOS and Windows Phone (and maybe Android, not sure) as Native.

It's doing the same thing with the Window control (and possibly others).

I've had to set specific keys for the ComboBox and Window controls in the web.config to tell them to render in lightweight mode.  After doing that they are being rendered properly on iOS and Windows Phone.

Also, even emulating an iPad on Chrome's developer tools renders the controls natively.

The version on my Telerik.Web.UI.dll is 2014.1.225.45.

Hi George,

Indeed, we have faced a RenderMode issue in Q1 2014 (version 2014.1.225) of Telerik UI for ASP.NET AJAX. Fortunately, it has been fixed with the release of Q1 2014 SP1 (version 2014.1.403).

Specifying a certain RenderMode value in the web.config for controls you find affected is one of the ways to handle the issue experienced. Just for reference, one can do that by adding to the web.config a key such as the following:

A more general way to overcome the RenderMode issue is to upgrade to Q1 2014 SP1.
In addition to RenderMode fixes, it incorporates other important fixes as well as improved experience under mobile devices. You can check the Q1 2014 SP1 release history for a complete items list.

Regards,
Dimitar
Telerik