WPF

private static bool IsEmailAllowed(string text)
        {
            bool blnVallidEmail = false;
            Regex regEMail = new Regex(@"^[a-zA-Z][\w\.-]{2,28}[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$");
            if (text.Length > 0)
            {
                if (!regEMail.IsMatch(text))
                {
                    MessageBox.Show("E-Mail expected", "Error", MessageBoxButton.OK, MessageBoxImage.Error);                    
                    blnVallidEmail = !regEMail.IsMatch(text);
                }
            }

            return blnVallidEmail;
        }

        private void txtEmail_PreviewTextInput(object sender, TextCompositionEventArgs e)
        {
            e.Handled = !IsEmailAllowed(e.Text);                    
        }

arkiboys wrote:

However, I am trying to use the following method instead which is due to the
requirements...

UpdateSourceTrigger=LostFocus, ValidatesOnDataErrors=true, NotifyOnValidationError=true

public string Error
{
    get { throw new NotImplementedException(); }
}

public string this[string columnName]
{
    get
    {
      string result = null;
      if (columnName == "Email") // Assuming your property is called Email.
      {
        Regex regEMail = new Regex(@"^[a-zA-Z][\w\.-]{2,28}[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$");
        bool isValid = regEmail.IsMatch(Email);
        if (!isValid)
        {
          result="You must enter an email";

        }
      }
      return result;
    }
}

ObservableCollection<DADirective> listdata;
        DADirective SelectDirective;
 public void LoadDirective()
        {
            //DerivedAttributeEntity oDAEEntity;
            listdata = new ObservableCollection<DADirective>();
            
            SelectDirective = (DADirective)lbDirectiveList.SelectedItem;
            
            listdata.Add(new DADirective { DirectiveName = "Filter trading account", DirectiveDescription = "Rows will Trading account value to be filtered" });
            listdata.Add(new DADirective { DirectiveName = "Filter Counter party rows", DirectiveDescription = "Rows where counter party is null will be filtered" });
            listdata.Add(new DADirective { DirectiveName = "Filter USD currency records", DirectiveDescription = "Filter those rows where currency is USD" });

            lbDirectiveList.ItemsSource = listdata;           
        }

Ian Shlasko wrote:

I agree that using "http" as the prefix is kind of silly (I'm guessing there was
some sort of reason for it, but not looking it up right now)... But it
works.