Inheriting Control makes theme disappear

[Michael]

I'm using Telerik Q2 and the OfficeBlue theme as my common theme for all of my controls as I'm using the RadRibbonBar with an Office 2k7 look and feel.

I attempted to extend the RadCheckBox control to implement a 3 state system the way I wanted to using the control as the base.  The problem was, when I added the new inherited control to the form, the theme was gone and I could not find a way to add it back.

The same issue is cauing havok for me especially with the Telerik CAB Enabling Kit.  I'm relying on using the RadTabStrip in my application, however the RadTabWorkspace needed for cab inherits from the RadTabStrip, and the same issue occurs, there's no theme on the control.  The tabs are ugly and in boxes.   Clicking on a tab has no VISUAL effect, even though the tab page switches.  It's impossible to tell the selected tab.

Is there any way to dynamically force a theme on a control at runtime or to have inherited controls inherit the themes as well?

Thanks,

Michael Gerety.

[Deyan]

Hello Michael,

Thanks for contacting us and for the provided details. Our theming mechanism works generally by matching the property settings defined in an XML theme with the type of the elements and the parent control in which they reside.

When you inherit a RadControl, say a RadCheckBox, and use it in your application, the theming mechanism only knows the RadCheckBox type and thus the theme will not be applied.

However, there is an easy way to fix that by overriding ThemeClassName property and returning the class name of the base RadCheckBox control:

public override string ThemeClassName
{
     get
     {
          return "Telerik.WinControls.UI.RadCheckBox";
     }
     set
     {
          base.ThemeClassName = value;
     }
}

You can place this property override in your inheriting class. You should also override this property in all classes which inherit from Telerik RadControls in order to prevent them from loosing their theme.

For example, for the RadTabStrip control you should use:

public override string ThemeClassName
{
     get
     {
          return "Telerik.WinControls.UI.RadTabStrip";
     }
     set
     {
          base.ThemeClassName = value;
     }
}

I hope this is helpful. Do not hesitate to write back if you need further assistance.

All the best,
Deyan
the Telerik team

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