Validation rule not working...

Hi there,

i have been trying to implement a custom validation rule. It doesn't seem to be working though I am not getting any errors. I figured out that I needed this line.

Code:

---

xmlns:local="clr-namespace:validatiinTest"

---

Yes - I know I spelled Validation wrong when I created the project.

Everything compiles but nothing happens when I change the value in the textbox that has the validation rule... I mean in the code, I dropped a breakpoint inside the validate method and it never gets called - what am I missing? Below is the code for the whole thing... As far as the book that I have is concerned that is everything I should need. Of course I am not doing anything or checking it but still Validate() should get called.

Code:

---

<Window x:Class="validatiinTest.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:validatiinTest"
    Title="Window1" Height="300" Width="300" Background="Aqua">
   
    <Grid>
        <TextBox Height="21" Margin="12,62,0,0" Name="TextBox1" VerticalAlignment="Top" HorizontalAlignment="Left" Width="120" >
            <TextBox.Text>
                <Binding  Path="xxxx" UpdateSourceTrigger="PropertyChanged">
                    <Binding.ValidationRules>
                        <local:CheckForInteger />
                    </Binding.ValidationRules>
                </Binding>
            </TextBox.Text>
        </TextBox>
        <TextBox Height="23" Margin="77,0,81,29" Name="textBox2" VerticalAlignment="Bottom" />
    </Grid>
</Window>

---

Code:

---

namespace validatiinTest
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }
    }

    public class CheckForInteger : ValidationRule
    {
        public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureinfo)
        {
            int theNum = 0;
            if (!int.TryParse(value.ToString(), out theNum))
                return new ValidationResult(false, "Not a number");
            return new ValidationResult(true, "No Error");
        }
    }
}

---

Thanks!

Have a look at Binding Validation Sample from MSDN if it helps.