Método que veirica se a string passada está no formado +x55(x21)9999999999

gistfile1.cs

/// <summary>
/// Método que veirica se a string passada está no formado +x55(x21)9999999999
/// </summary>
/// <param name="phoneNumber"></param>
/// <returns></returns>
public bool CheckPhoneMask(string phoneNumber) {
    bool returnValue = StringUtility.IsARegexMatch(@"^(?<DDI>\+?[0-9]{1,3})?\((?<DDD>[0-9]{1,3})\)(?<NUMBER>[0-9]{1,9})$", phoneNumber.Replace("-", ""));

    return returnValue;
}