In this case you can try to set the BorderBrush for the ValueEditorCheckBox inside the ControlTemplate :

<Style TargetType="{x:Type igEditors:XamCheckEditor}">
     <Setter Property="Template">
        <Setter.Value>
  <ControlTemplate TargetType="{x:Type igEditors:XamCheckEditor}">
   <Border x:Name="MainBorder"
    BorderBrush="{TemplateBinding BorderBrush}"
    BorderThickness="{TemplateBinding BorderThickness}"
    Background="{TemplateBinding Background}">
   <igEditors:ValueEditorCheckBox x:Name="PART_FocusSite"
    IsChecked="{Binding RelativeSource={RelativeSource TemplatedParent},
    Path=IsChecked, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
    IsThreeState="{TemplateBinding IsThreeState}"
    HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
    VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
    Margin="{TemplateBinding Padding}">
   </igEditors:ValueEditorCheckBox>
   </Border>
   
  <ControlTemplate.Triggers>
   <Trigger Property="IsEmbedded" Value="False"/>
   <Trigger Property="ReadOnly" Value="True">
    <Setter TargetName="PART_FocusSite" Property ="IsEnabled" Value="False" />
   </Trigger>
   <Trigger Property="IsChecked" Value="False">
    <Setter TargetName="PART_FocusSite" Property ="BorderBrush" Value="Red" />
   </Trigger>
  </ControlTemplate.Triggers>
  
  </ControlTemplate>
  </Setter.Value>
  </Setter>
  
    <Style.Triggers>
 <Trigger Property="IsEmbedded" Value="False">
  <Setter Property="BorderThickness" Value="1" />
 </Trigger>
    </Style.Triggers>
</Style>

Regards

Vlad

What about BorderBrush instead of Background? Will it work?

<Style TargetType="{x:Type igEditors:XamCheckEditor}">
              <Style.Triggers>
                           <Trigger Property="IsChecked" Value="False">
                                           <Trigger.Setters>
                                                        <Setter Property="ToolTip" Value="Check" />
                                                        <Setter  Property="BorderBrush" Value="Red" />
                                             </Trigger.Setters>
                            </Trigger>
               </Style.Triggers>
 </Style>

Hello,

IsValueValid can't be used with the XamCheckEditor because it is returning only "true" value. Instead you can use the IsChecked property for that perpose :

<Style TargetType="{x:Type igEditors:XamCheckEditor}">
              <Style.Triggers>
                           <Trigger Property="IsChecked" Value="False">
                                           <Trigger.Setters>
                                                        <Setter Property="ToolTip" Value="Check" />
                                                        <Setter  Property="Background" Value="Red" />
                                             </Trigger.Setters>
                            </Trigger>
               </Style.Triggers>
 </Style>

Hope this helps

Vlad

I am using XamDataGrid Validation Feature.In the XamDataGrid i am validating the XamCheckEditor

Value whether the user selects the XamCheckEditor. I am able to set the Tooltip but i unable to set the

BorderBrush to Red. The following code doesn't have any effect.

 <Style.Triggers>  

                        <Trigger Property="IsValueValid" Value="false">  

                            <Trigger.Setters>  

                                <Setter Property="BorderBrush" Value="Red" />  

                            </Trigger.Setters>  

                        </Trigger>  

                    </Style.Triggers>