public void Append(IDailyList dailyList)
        {
            DailyListSerializer serializer = new DailyListSerializer();

            using (StreamWriter writer = File.AppendText(this.FileName))
            {
                string line = serializer.Serialize(dailyList);
                writer.WriteLine(line);
            }
        }
        public string Serialize(IDailyList list)
        {
            StringBuilder sb = new StringBuilder();

            sb.AppendFormat("{0}\t{1}\t{2}", list.Date.Year, list.Date.Month, list.Date.Day);

            foreach (ExchangeRate rate in list)
                sb.AppendFormat("\t{0}\t{1}", rate.Currency, rate.Rate.ToString(CultureInfo.InvariantCulture));

            return sb.ToString();
        }
 public void Add(IDailyList dailyList)
 {
     if (!this.GetDateToList().ContainsKey(dailyList.Date))
         new DailyListFile().Append(dailyList);
 }