validation doesnt work (message doesnt show)

[Rainson12]

Im trying to add validation to your sample but the validation message doesnt show. The validation executes but the validation message will never be shown. This seems to be an issue of the WindowChrome.WindowChrome stuff in the MainWindow. If i remove the WindowChrome stuff the validation message shows up. Heres an example:

<TextBox x:Name="NameTextBox" VerticalAlignment="Top"> <TextBox.Text> <Binding Path="FirstName" UpdateSourceTrigger="PropertyChanged"> <Binding.ValidationRules> <validations:NotEmptyValidationRule ValidatesOnTargetUpdated="True" /> </Binding.ValidationRules> </Binding> </TextBox.Text> <Validation.ErrorTemplate> <ControlTemplate> <StackPanel> <!-- Placeholder for the TextBox itself --> <AdornedElementPlaceholder x:Name="textBox"/> <TextBlock Text="{Binding [0].ErrorContent}" Foreground="Red"/> </StackPanel> </ControlTemplate> </Validation.ErrorTemplate> </TextBox>

public class NotEmptyValidationRule : ValidationRule { public override ValidationResult Validate(object value, CultureInfo cultureInfo) { var test = string.IsNullOrWhiteSpace((value ?? "").ToString()) ? new ValidationResult(false, "Field is required.") : ValidationResult.ValidResult; return test; } }

[Rainson12]

a fix would be to change the PageHost.xaml to
<AdornerDecorator> <Grid> <ContentControl x:Name="OldPage" /> <ContentControl x:Name="NewPage" /> </Grid> </AdornerDecorator>

[angelsix]

Works fine without any changes to latest source code

   <!-- Email -->
    <TextBox 
                Tag="Email"
                local:IsFocusedProperty.Value="True"
                >
        <TextBox.Text>
            <Binding Path="Email" UpdateSourceTrigger="PropertyChanged">
                <Binding.ValidationRules>
                    <local:NotEmptyValidationRule ValidatesOnTargetUpdated="True" />
                </Binding.ValidationRules>
            </Binding>
        </TextBox.Text>
        <Validation.ErrorTemplate>
            <ControlTemplate>
                <StackPanel>
                    <!-- Placeholder for the TextBox itself -->
                    <AdornedElementPlaceholder x:Name="textBox"/>
                    <TextBlock Text="{Binding [0].ErrorContent}" Foreground="Red"/>
                </StackPanel>
            </ControlTemplate>
        </Validation.ErrorTemplate>
    </TextBox>

No repro