Windows Phone 7 Textbox validation. I ONLY want numbers

I cant' seem to get this to work.. On the WP7 the '%' is the same as the '5' as far as the e.Key is concerned.. How do I ONLY get the numbers...

Or is there a open srouce WP7 textbox control that would work similiar to the AJAX control toolkit stuff so I can say.. Here is a TextBox.. ONLY ALLOW NUMBERS..?

if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control)
        {
            e.Handled = false;
            return;
        }

then entire function is

  private void HandleKeyEvent(KeyEventArgs e)
    {
        e.Handled = true;

        if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control)
        {
            e.Handled = false;
            return;
        }

        if (e.Key == Key.Back || e.Key == Key.Delete || e.Key == Key.Left || e.Key == Key.Right ||
            e.Key == Key.D0 || e.Key == Key.D1 || e.Key == Key.D2 || e.Key == Key.D3 || e.Key == Key.D4 || e.Key == Key.D5 || e.Key == Key.D6 ||
            e.Key == Key.D7 || e.Key == Key.D8 || e.Key == Key.D9 ||
            e.Key == Key.NumPad0 || e.Key == Key.NumPad1 || e.Key == Key.NumPad2 || e.Key == Key.NumPad3 || e.Key == Key.NumPad4 || e.Key == Key.NumPad5 || e.Key == Key.NumPad6 ||
       开发者_如何学Go     e.Key == Key.NumPad7 || e.Key == Key.NumPad8 || e.Key == Key.NumPad9)
        {
            e.Handled = false;
            //return;
        }

        if ((e.Key == Key.Subtract || (e.Key == Key.Unknown && e.PlatformKeyCode == 189)) && base.SelectionStart == 0 && (base.Text.Length == 0 || base.Text[0] != '-'))
        {
            e.Handled = false;
        }

        if (this.Text.Length > 3)
        {
            e.Handled = true;
        }    
    }

The following link will be of great use to you I believe TextBox Numbers Only WP7. It explains what you desire in detail.