Validation du courrier électronique dans une application C # Winforms

Le meilleur moyen serait de transmettre cette tâche de validation à .NET elle-même: xxx

accordé, il incendiera des faux positifs sur certaines adresses électroniques techniquement valides (avec des caractères non latins, pour Exemple), mais comme il ne sera pas en mesure d'envoyer à ces adresses, vous pouvez aussi bien les filtrer à partir du début.

J'ai utilisé la regex à partir d'un plugin JQuery qui valide du côté du client: xxx pré>

@ "^ (((([! # \ d | \ $% & '* + - / = \? \ ^ {\ |} ~] | [\ u00a0- \ ud7ff \ ufdf0- \ ufff]) + ([[[AZ] | \ d | [! # \ $% & '\ * \ + \ - \ / = \? \ ^ _ code> {\ |} ~] | [\ u00a0- \ ud7ff \ uf900- \ ufdcf \ ufdf0 - \ uffef]) +) *) | ((\ x22) (((((\ x20 | \ x09) * (\ x0d \ x0a))? (\ x20 | \ x09) +)? \ x08 \ x0b \ x0c \ x0e- \ x1f \ x7f] | \ x21 | [\ x23- \ x5b] | [\ x5d- \ x7e] | [\ u00a0- \ ud7ff \ uf900- \ ufdcf \ ufdf0- \ uffef ]) | (\ ([\ x01- \ x09 \ x0b \ x0c \ x0d- \ x7f] | [\ u00a0- \ ud7ff \ ufdf0- \ ufff \ ufdf0- \ ufff])))) * (((((\ x20 | \ x09) * (\ x0d \ x0a))? (\ x20 | \ x09) +)? (\ x22))) @ ((([AZ] | \ D | [\ u00a0- \ ud7ff \ uf900- \ ufdcf \ ufdf0- \ uffef]) | ((az] | \ d | ufdf0- \ ufdcf \ ufdf0- \ ufdcf]) ([AZ] | \ D | - |. | em> | ~ | [\ u00a0- \ ud7ff \ uf900- \ ufdcf \ ufdf0- \ ufff]) ([az] | \ d | [\ u00a0- \ ud7ff \ ufdf0- \ ufff \ ufdf0- \ uffef ]))) ufdf0- \ uffef]) ([az] | \ d | - |. | _ | ~ | [\ u00a0- \ ufdcf \ ufdf0- \ ufff]) em> ([AZ] | [ \ u00a0- \ ud7ff \ uf900- \ ufdcf \ u FDF0- \ UFFF])))).? $ ", Regexoptions.Compiled); p>

  return regex.IsMatch(email);
}

en utilisant article de Chris ', j'ai fait une extension Méthode des chaînes qui lient une bibliothèque DnsLookup (crédit est donnée à Bill Andreozzi, billandr@towncallpass.com dans la source), la mise en œuvre de Telnet minimal de Tom Janssens ( http://www.corebvba.be ) et ma propre regex pour valider les adresses électroniques:

/// <summary>
/// The regular expression to test the string against.
/// </summary>
private static readonly Regex validEmailRegex = new Regex(
    @"^(([^<>()[\]\\.,;:\s@\""]+"
    + @"(\.[^<>()[\]\\.,;:\s@\""]+)*)|(\"".+\""))@"
    + @"((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}"
    + @"\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+"
    + @"[a-zA-Z]{2,}))$",
    RegexOptions.Compiled);

/// <summary>
/// Determines whether the specified string is a valid email address.
/// </summary>
/// <param name="value">
/// The string to validate.
/// </param>
/// <returns>
/// <c>true</c> if the specified string is a valid email address;
/// otherwise, <c>false</c>.
/// </returns>
public static bool IsValidEmailAddress(this string value)
{
    if (!validEmailRegex.IsMatch(value))
    {
        return false;
    }

    var mailServer = new DNS().LookupMX(value.Split('@')[1]);

    if (!mailServer.MoveNext())
    {
        return false;
    }

    var telnet = new TelnetConnection(((DNS_MX_DATA)((DNS_WRAPPER)mailServer.Current).dnsData).pNameExchange, 25);

    try
    {
        if (!TelnetCompare(telnet.Read(), "220"))
        {
            return false;
        }

        telnet.WriteLine("helo hi");
        if (!TelnetCompare(telnet.Read(), "250"))
        {
            return false;
        }

        telnet.WriteLine("mail from: " + value);
        if (!TelnetCompare(telnet.Read(), "250"))
        {
            return false;
        }

        telnet.WriteLine("rcpt to: " + value);
        if (!TelnetCompare(telnet.Read(), "250"))
        {
            return false;
        }
    }
    finally
    {
        telnet.WriteLine("quit");
    }

    return true;
}

/// <summary>
/// Compares two strings for length and content from the Telnet stream.
/// </summary>
/// <param name="input">The input string.</param>
/// <param name="response">The desired response.</param>
/// <returns>true if the response is the first characters if the input,
/// false otherwise</returns>
private static bool TelnetCompare(string input, string response)
{
    if (string.IsNullOrEmpty(input) || string.IsNullOrEmpty(response))
    {
        return false;
    }

    if (input.Length < response.Length)
    {
        return false;
    }

    return string.CompareOrdinal(input.Substring(0, response.Length), response) == 0;
}

private void textBox1_Validating(object sender, CancelEventArgs e)
{
System.Text.RegularExpressions.Regex rEMail = new System.Text.RegularExpressions.Regex(@"^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$");
if (textBox1.Text.Length > 0)
{
if (!rEMail.IsMatch(textBox1.Text))
{
MessageBox.Show("E-Mail expected", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
textBox1.SelectAll();
e.Cancel = true;
}
}
}

regex reg = nouvelle regex (@ "\ w + ([- +.] \ w +) @ \ w + ([-.] \ w +) em>. \ w + ([-.] \ w + ) * ");

/// Initialisation de l'objet pour REGEX P>

        if (!reg.IsMatch(email.Text.Trim()))


        {
            errorProvider1.SetError(email, "Please provide a valid Email Address");

            email.Focus();

            return;

        }

if (dateEdit1.EditValue == null || textEdit11.EditValue == null || textEdit10.EditValue == null || comboBox1.Text == null
      || textEdit12.EditValue == null || dateEdit2.EditValue == null || textEdit12.EditValue == null || comboBox2.Text == null
      || comboBox2.Text == null || textEdit14.EditValue == null || textEdit15.EditValue == null || textEdit16.EditValue == null
      || textEdit17.EditValue == null || textEdit18.EditValue == null || comboBox5.Text == null || textEdit19.EditValue == null)
{
    XtraMessageBox.Show("Please submit the record");
}
else
{
    DialogResult dialog = XtraMessageBox.Show("Are you sure you want to remove this record?", "Delete Record", MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
    if (dialog == DialogResult.OK)
    {
        String st = "DELETE FROM OutPatient WHERE OutPatientID =" + textEdit8.Text;

        SqlCommand com = new SqlCommand(st, con);
        con.Open();
        try
        {
            com.ExecuteNonQuery();

        }
        catch (SqlException)
        {
            con.Close();
        }
        ClearOutPatient();

    }
    else if (dialog == DialogResult.Cancel)
    {
        ClearOutPatient();
    }