Hi Dan,
I attached a sample control library with a text box that has an
ErrorState property. The text box (CustomTextBox) can be themed with Visual Style Builder - just use "Load Control" -> "From Assembly" menu and select the control library's assembly.
In the sample, the default theme is in CustomTextBoxDefault.xml. In that theme, when
ErrorState is
IncorrectText the background color becomes red.
Regards,
Angel
the Telerik team
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