I am working on trying to get the data verification to work with WPF and cannot seem to figure out how to use the verification built into DevForce.  I currently added the below code to my app.xaml and am getting the notices of errors however, the error messages are not correct.

On a field that is required, I am getting this error:
Exception has been thrown by the target of an invocation.

Then on a field that is not required and left blank, I am getting this error:
Input string was not in a correct format.

Are there any examples on how to use the built in DevForce verification with WPF?

Here is what I have in my app file:

        <ControlTemplate x:Key="validationTemplate">

            <DockPanel>

                <TextBlock Margin="5,0,5,0" Foreground="Red" FontSize="16" VerticalAlignment="Center" Text="*" ToolTip="{Binding ElementName=errorAdorner, Path=AdornedElement.(Validation.Errors)[0].ErrorContent}" />

                <AdornedElementPlaceholder x:Name="errorAdorner" />

            </DockPanel>

        </ControlTemplate>

        <Style TargetType="{x:Type TextBox}">

            <Setter Property="Validation.ErrorTemplate" Value="{StaticResource validationTemplate}" />

        </Style>

Here is an example of one of my textboxes:

            <TextBox Grid.Column="1" Grid.Row="5" Text="{Binding CurrentVehicle.Description, Mode=TwoWay, UpdateSourceTrigger=LostFocus, NotifyOnValidationError=True, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}" HorizontalAlignment="Stretch" VerticalAlignment="Top" Height="Auto" Width="Auto" />

>> Exception has been thrown by the target of an invocation.

Here’s some text from the discussion of WPF validation in Matthew MacDonald’s book on WPF that may be relevant (p.543):

“If you’re using custom validation rules, you’ll almost certainly choose to place the error information in the ValidationError.ErrorContent propety. If you’re using the ExceptionValidationRule, the ErrorContent property will return the Message property of the corresponding exception. However, there’s a catch. If an exception occurs because the data type cannot be cast to the approprate value, the ErrorContent works as expected and reports the problem. However, if the property setter in the data object throws an exception, this exception is wrapped in a TargetInvocationException, and the ErrorContent provides the text from the TargetInvocationException.Message property, which is the much less helpful warning ‘Exception has been thrown by the target of an invocation.’

“Thus, if you’re using your property setters to raise exceptions, you’ll need to add code that checks the InnerException property of the TargetInvocationException. If it’s not null, you can retrieve the original exception object and use its Message property instead of the ValidationError.ErrorContent property.”

Greg, are there any examples on how to properly use devforce validation with WPF?

Yes, mee to - I would really like to see an example with WPF validation.