C# Calendar.GetEra方法代码示例

	public void FromDateTime(Calendar cal, DateTime time) {
		Date dmy = new Date();
		dmy.Day = cal.GetDayOfMonth(time);
		dmy.Month = cal.GetMonth(time);
		dmy.Year = cal.GetYear(time);
		dmy.Era = cal.GetEra(time);
		Day = dmy.Day;
		Month = dmy.Month;
		Year = dmy.Year;
		Era = dmy.Era;
	}

      /// <summary>
      /// Initializes a new instance of the <see cref="MonthCalendarDate"/> class.
      /// </summary>
      /// <param name="cal">The calendar to use.</param>
      /// <param name="date">The gregorian date.</param>
      /// <exception cref="ArgumentNullException">If <paramref name="cal"/> is <c>null</c>.</exception>
      public MonthCalendarDate(Calendar cal, DateTime date)
      {
         if (cal == null)
         {
            throw new ArgumentNullException("cal", "parameter 'cal' cannot be null.");
         }

         if (date < cal.MinSupportedDateTime)
         {
            date = cal.MinSupportedDateTime;
         }

         if (date > cal.MaxSupportedDateTime)
         {
            date = cal.MaxSupportedDateTime;
         }

         this.Year = cal.GetYear(date);
         this.Month = cal.GetMonth(date);
         this.Day = cal.GetDayOfMonth(date);
         this.Era = cal.GetEra(date);
         this.calendar = cal;
      }

      /// <summary>
      /// Determines if the specified <paramref name="year"/> is a valid year value.
      /// </summary>
      /// <param name="year">The year value.</param>
      /// <param name="cal">The calendar to use.</param>
      /// <param name="era">The era the year belongs to.</param>
      /// <returns>true if it's a valid year value; false otherwise.</returns>
      private static bool IsValidYear(int year, Calendar cal, int era)
      {
         int minYear = cal.GetYear(cal.MinSupportedDateTime.Date);
         int maxYear = cal.GetYear(cal.MaxSupportedDateTime.Date);

         if (cal.Eras.Length > 1)
         {
            DateTime? minDate = null, maxDate = null;

            DateTime date = cal.MinSupportedDateTime;

            while (date < cal.MaxSupportedDateTime.Date)
            {
               int e = cal.GetEra(date);

               if (e == era)
               {
                  if (minDate == null)
                  {
                     minDate = date;
                  }

                  maxDate = date;
               }

               date = cal.AddDays(date, 1);
            }

            minYear = cal.GetYear(minDate.GetValueOrDefault(cal.MinSupportedDateTime.Date));
            maxYear = cal.GetYear(maxDate.GetValueOrDefault(cal.MaxSupportedDateTime.Date));
         }

         year = cal.ToFourDigitYear(year);

         return year >= minYear && year <= maxYear;
      }

        /// <summary>
        /// Builds an array of <see cref="MonthCalendarEraRange"/> to store the min and max date of the eras of the specified
        /// <see cref="System.Globalization.Calendar"/>.
        /// </summary>
        /// <param name="cal">
        /// The <see cref="System.Globalization.Calendar"/> to retrieve the era ranges for.
        /// </param>
        /// <returns>
        /// An array of type <see cref="MonthCalendarEraRange"/>.
        /// </returns>
        private static MonthCalendarEraRange[] GetEraRanges(Calendar cal)
        {
            if (cal.Eras.Length == 1)
            {
                return new[] { new MonthCalendarEraRange(cal.Eras[0], cal.MinSupportedDateTime.Date, cal.MaxSupportedDateTime.Date) };
            }

            List<MonthCalendarEraRange> ranges = new List<MonthCalendarEraRange>();
            DateTime date = cal.MinSupportedDateTime.Date;
            int currentEra = -1;
            while (date < cal.MaxSupportedDateTime.Date)
            {
                int era = cal.GetEra(date);

                if (era != currentEra)
                {
                    ranges.Add(new MonthCalendarEraRange(era, date));
                    if (currentEra != -1)
                    {
                        ranges[ranges.Count - 2].MaxDate = cal.AddDays(date, -1);
                    }

                    currentEra = era;
                }

                date = cal.AddDays(date, 1);
            }

            ranges[ranges.Count - 1].MaxDate = date;
            return ranges.ToArray();
        }

 protected virtual void GetDateFormatValues(DateParts parts, Calendar calendar, out int twoDigitYear, out string monthName, out string monthNameShort, out string monthNameGenitive, out string monthNameShortGenitive, out string dayName, out string dayNameShort, out string eraName, out string eraNameShort) {
     var yearString = parts.Year.ToString("00", System.Globalization.CultureInfo.InvariantCulture);
     twoDigitYear = Int32.Parse(yearString.Substring(yearString.Length - 2));
     monthName = parts.Month > 0 ? _dateTimeFormatProvider.MonthNames[parts.Month - 1] : null;
     monthNameShort = parts.Month > 0 ? _dateTimeFormatProvider.MonthNamesShort[parts.Month - 1] : null;
     monthNameGenitive = parts.Month > 0 ? _dateTimeFormatProvider.MonthNamesGenitive[parts.Month - 1] : null;
     monthNameShortGenitive = parts.Month > 0 ? _dateTimeFormatProvider.MonthNamesShortGenitive[parts.Month - 1] : null;
     dayName = parts.Day > 0 ? _dateTimeFormatProvider.DayNames[(int)calendar.GetDayOfWeek(parts.ToDateTime(calendar))] : null;
     dayNameShort = parts.Day > 0 ? _dateTimeFormatProvider.DayNamesShort[(int)calendar.GetDayOfWeek(parts.ToDateTime(calendar))] : null;
     eraName = parts.Day > 0 ? _dateTimeFormatProvider.GetEraName((int)calendar.GetEra(parts.ToDateTime(calendar))) : null;
     eraNameShort = parts.Day > 0 ? _dateTimeFormatProvider.GetShortEraName((int)calendar.GetEra(parts.ToDateTime(calendar))) : null;
 }