I'm using a WPF validation for TextBox validation. I have defined this Template: ``` ``` The TextBox is located on a form in a TabItem. Everything works fine, but the '!' TextBlock stay…

WPF ErrorTemplate visible when not focused?

focus, templates, validation, wpf

Solution

This is what we do...

<Style x:Key="ErrorTemplate" TargetType="Control">
    <Setter Property="Validation.ErrorTemplate">
        <Setter.Value>
            <!--Set your error template in here-->
        </Setter.Value>
    </Setter>
    <Style.Triggers>
        <Trigger Property="IsVisible" Value="false">
            <Setter Property="Validation.ErrorTemplate" Value="{x:Null}"/>
        </Trigger>
    </Style.Triggers>
</Style>

Problem

I'm using a WPF validation for TextBox validation. I have defined this Template: ``` <Style x:Key="textBoxInError" TargetType="{x:Type TextBox}" BasedOn="{StaticResource StyleTextBox}"> <Style.Triggers> <Trigger Property="Validation.HasError" Value="true"> <Setter Property="ToolTip" Value="{Binding RelativeSource={x:Static RelativeSource.Self}, Path=(Validation.Errors)[0].ErrorContent}"/> <Setter Property="Background" Value="{StaticResource TextBox_ErrorBackgroundBrush}"/> <Setter Property="BorderBrush" Value="{StaticResource TextBox_ErrorBorderBrush}"/> <Setter Property="BorderThickness" Value="2"/> </Trigger> </Style.Triggers> <Setter Property="Validation.ErrorTemplate"> <Setter.Value> <ControlTemplate> <DockPanel> <TextBlock DockPanel.Dock="Right" Foreground="Red" FontSize="20" Text="!"/> <AdornedElementPlaceholder/> </DockPanel> </ControlTemplate> </Setter.Value> </Setter> </Style> ``` The TextBox is located on a form in a TabItem. Everything works fine, but the '!' TextBlock stays visible when I choose other TabItems. This behaviour is observed in many other cases - when expander expands etc.. the Excklamation always stays visible on the same place, although the TextBox is not diplayed.

Original source