xenadmin/XenCenterLib/EmailAddressValidator.cs

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using System;
using System.Net.Mail;

namespace XenCenterLib
{
    /// <summary>
    /// Validates an email address. 
    /// </summary>
    public class EmailAddressValidator
    {
        /// <summary>
        /// Validates an email address. Null, empty, or strings containing forbidden chars
        /// will return false. Otherwise validity is checked using a MS class.
        /// 
        /// Note: This uses FormatException to control flow.
        /// </summary>
        /// <returns>email address is valid</returns>
        public bool IsValid(string emailAddress)
        {
            if (String.IsNullOrEmpty(emailAddress))
                return false;

            if (ContainsForbiddenCharacters(emailAddress))
                return false;

            MailMessage mm = new MailMessage();
            try
            {
                mm.To.Add(emailAddress);
                return true;
            }
            catch (FormatException) //Thrown if an ill-formed email address is given
            {
                return false;
            }
        }

        private bool ContainsForbiddenCharacters(string emailAddress)
        {
            char[] forbiddenCharacters = new []
                                             {
                                                 '(',
                                                 ')',
                                                 ' '
                                             };

            if (emailAddress.IndexOfAny(forbiddenCharacters) == -1)
                return false;
            return true;
        }
    }
}