remove red rectangle around combobox

Question

i need to remove red rectangle around combobox. I have setup combobox in xaml like (below) this and i`m trying to override of the Validation.ErrorTemplate.

        <ComboBox x:Name="comboPodkategoria" 
                            Margin="0,3,0,0"
                            IsSynchronizedWithCurrentItem="False" 
                            IsEditable="False"
                            ItemsSource="{Binding Source={StaticResource PodKategoriaLookup}, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}"
                            SelectedValue="{Binding IDPodKategoria}"
                            DisplayMemberPath="kat_popis" SelectedValuePath="IDPodkat" TabIndex="5" Style="{StaticResource combostyle}">
                            <Validation.ErrorTemplate>
                                <ControlTemplate>
                                </ControlTemplate>
                            </Validation.ErrorTemplate> 
            </ComboBox>

And style for removing red rectangle, but a have some error in xaml saying that Visibility property is not recognized or is not accessible. Style definition is below.

<Style x:Key="combostyle">
<Style.Triggers>
    <Trigger Property="Validation.HasError" Value="True">
        <Setter Property="Visibility" TargetName="NotValid" Value="Visible"/>
    </Trigger>  
</Style.Triggers>   

Any idea? :(

Solution 1

Use this to modify the Validation.ErrorTemplate

<ControlTemplate x:Key="ComboBoxValidationErrorTemplate">
    <DockPanel>
        <Border BorderBrush="Blue" BorderThickness="4">
            <AdornedElementPlaceholder />
        </Border>
    </DockPanel>
</ControlTemplate>

And then use it in your ComboBox like

<ComboBox Validation.ErrorTemplate="{StaticResource ComboBoxValidationErrorTemplate}"
          ...>

To have no indication of a Validation Error, remove the DockPanel, set Visibility to Collapsed or any other way you like.

Almost forgot, probably the easiest way to remove the "Red Border"

<ComboBox Validation.ErrorTemplate="{x:Null}"
          ...>

Solution 2

Add your Combobox, Validation.ErrorTemplate="{x:Null}" ; this code is ignore errors.

Comments

[vikox]

Perfect, thank you. The last option is perfect for me, i didn`t know that.

[BSalita]

+1 for Validation.ErrorTemplate="{x:Null}". I'm experiencing the joy of a "exactly right" UI element.

[Mark]

+1 for Validation.ErrorTemplate="{x:Null}", awesome one, Thanks.

[mkb]

But is it ok to remove red validation rectangle in such case, doesn't it mean that binding is failing? also shouldn't it be done by OneWay binding since the ItemsSource is bound to a StaticResource? as in : ItemsSource="{Binding Source={StaticResource PodKategoriaLookup, Mode=OneWay},

[Fredrik Hedblad]

@mkb: It is a visual indication of a validation error on a binding. If you want to modify or remove that visual indication, for whatever reason, then it can be done like in the examples above.

[Wish]

I dont have much experience in WPF, but are there such nonsenses with textboxes?