WPF Binding Validation Rule issue

Question

I'm working on a simple WPF application and I'm stucked on something I'm sure very simple but I cannot find the solution even after many searchs.

The question is about a validation rule on a TextBox Text property binding.

I'd like to simply generate a message when the text entered in the textbox isn't validated.

I followed those two pages on the subject:

http://msdn.microsoft.com/fr-fr/library/ms752347(v=vs.110).aspx

http://www.codeproject.com/Articles/15239/Validation-in-Windows-Presentation-Foundation

but I cannot find where I'm wrong.

Here's a sample of my code:

XAML part :

    <TextBox x:Name="deviceIPAddressTextBox" HorizontalAlignment="Left" Height="23" Margin="109,10,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120" FontStyle="Italic">
       <TextBox.Text>
          <Binding Path="Address" UpdateSourceTrigger="LostFocus" Mode="TwoWay">
             <Binding.ValidationRules>
                <ExceptionValidationRule/>
             </Binding.ValidationRules>
          </Binding>
       </TextBox.Text>
    </TextBox>

Code part:

    public partial class MainWindow : Window
    {
       public Device CurrentDevice; 

       public MainWindow()
       {
          CurrentDevice = new Device();
          InitializeComponent();
          deviceIPAddressTextBox.DataContext = CurrentDevice;
       }

with Device class like that:

    public class Device : INotifyPropertyChanged
    {
       public event PropertyChangedEventHandler PropertyChanged;

       private string _Address;
       public string Address
       {
          get { return _Address; }
          set
          {
            if (string.IsNullOrEmpty(value)
            {
                _Address = "Enter IP Address";
                OnPropertyChanged("Address");
                return;
            }

            IPAddress ipAddress;
            if (IPAddress.TryParse(value, out ipAddress))
            {
                _Address = value;
                OnPropertyChanged("Address");
            }
            else
            {
                throw new ApplicationException("Not valid IP");
            }
          }
       }

       public Device()
       {
          Address = "Enter IP Address";
       }

       private void OnPropertyChanged(string propertyName)
       {
          if (PropertyChanged != null)
             PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
       }
    }

Following the different tutos I read when firing the ApplicationException I should have something like the TextBox border red (WPF default) but instead I've got a classic "Not handled exception"

Could you please help me on that?

Many thanks.

Update 1 : Part of answer

Even if I have the Visual Studio "Unhandled exception" I actually have the excepted behavior on the UI... so the question is How to manage correctly the exception throw ?

The article you followed is old. take a look at hirenkhirsaria.blogspot.co.il/2013/05/… — Jossef Harush
Thanks you Jossef I'll followed the link and keep you update on my issue. — BiwiGreg
using INotifyDataError interface was indeed solution. However I had to implement corpse of GetErrors method which is not done in the tutorial. — BiwiGreg

BiwiGreg BiwiGreg · Accepted Answer · 2014-04-17T10:39:28

using INotifyDataError interface was indeed solution.

I followed article linked by Jossef Harush : http://hirenkhirsaria.blogspot.co.il/2013/05/wpf-input-validation-using-mvvm.html

However I had to implement corpse of GetErrors method which is not done in the tutorial.

Thanks for your help!

WPF Binding Validation Rule issue

1 Answers