Last Updated: 22 Mar 2019 13:24 by ADMIN
Created on: 05 Feb 2019 17:10
Category: ComboBox
Type: Bug Report
NonEditable Background of ToggleButton Not Set

It looks like the `Fluent` themes may not properly theme the Non-Editable RadComboBox control.


Within the default style for RadComboBox within Telerik.Windows.Controls.Input.xaml, there exists a RadToggleButton with the name "PART_DropDownButton" which is part of the main control template. This toggle button uses the style "NonEditableComboToggleButtonStyle", which then sets the toggle button template to the "NonEditableComboToggleButtonControlTemplate" control template.


This control template has a Border named "ToggleButtonBackground" where to background is set to a template binding. However, the NonEditableComboToggleButtonStyle does not set background, and it therefore leads to a control that looks like the attached image.


This can be fixed by overriding the RadComboBox style, but it isn't simple to set the background on the ToggleButton, so you need to create custom templates and style to do it.

Attached Files:
1 comment
Posted on: 11 Feb 2019 13:04
Hi Tristan,

I tried my best to reproduce the behavior that you described.

The only way that I was able to replicate it was by mixing Xaml and NoXaml dlls, which is incorrect and may cause such inconsistencies. There are two mechanisms that can be used to set a theme and they are:
  • using implicit styles, i.e. NoXaml dlls
  • using StyleManager, i.e. Xaml dlls
The above mentioned approaches are independent.

Merging theme resource dictionaries when using StyleManager (mixing implicit styles theming and StyleManager) is not supported. StyleManager should be used only with the Xaml dlls, and Implicit Styles - only with the NoXaml binaries.

If you need more information on how to set a theme, using our controls, here is a detailed documentation article which explains the differences between the above mentioned theming mechanisms.

Please let me know whether using the desired mechanism with the respective required binaries solves your issue.

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