C# Calendar.GetDayOfYear方法代碼示例

 private void ExecutePosTest(string errorNum1, string errorNum2, Calendar myCalendar, int year,
     int month, int day, CalendarWeekRule rule, DayOfWeek firstDayOfWeek)
 {
     DateTime time;
     int actualDayOfYear, expectedDayOfYear;
     int weekOfYear;
     time = myCalendar.ToDateTime(year, month, day, 0, 0, 0, 0);
     expectedDayOfYear = myCalendar.GetDayOfYear(time);
     weekOfYear = myCalendar.GetWeekOfYear(time, rule, firstDayOfWeek);
     actualDayOfYear = this.GetDayOfYear(time, rule, firstDayOfWeek, weekOfYear, myCalendar);
     Assert.Equal(expectedDayOfYear, actualDayOfYear);
 }

        private int GetDayOfYear(DateTime time, CalendarWeekRule rule, DayOfWeek firstDayOfWeek, int weekOfYear, Calendar myCalendar)
        {
            int retVal = -367;
            int offset = 0;
            int dayOfWeekForJan1, dayOfYear, dayOfWeek;
            dayOfYear = myCalendar.GetDayOfYear(time); //1-based
            dayOfWeek = (int)myCalendar.GetDayOfWeek(time) - (int)firstDayOfWeek + 1; //1-based
            if (dayOfWeek <= 0)
                dayOfWeek += c_DAYS_PER_WEEK; //Make it a positive value
            dayOfWeekForJan1 = dayOfWeek - (dayOfYear - 1) % c_DAYS_PER_WEEK; //1-based
            if (dayOfWeekForJan1 <= 0)
                dayOfWeekForJan1 += c_DAYS_PER_WEEK; //Make it a positive value
                                                     // When the day of specific time falls on the previous year,
                                                     // return the number of days from January 1 directly.
                                                     // There could be 6 weeks within a month.
            if (time.Month == 1 && weekOfYear > 6)
            {
                return dayOfWeek - dayOfWeekForJan1 + 1;
            }

            switch (rule)
            {
                case CalendarWeekRule.FirstDay:
                    offset = dayOfWeek - dayOfWeekForJan1;
                    break;
                case CalendarWeekRule.FirstFourDayWeek:
                    if (dayOfWeekForJan1 <= 4)
                    {
                        offset = dayOfWeek - dayOfWeekForJan1;
                    }
                    else
                    {
                        offset = dayOfWeek + c_DAYS_PER_WEEK - dayOfWeekForJan1;
                    }

                    break;
                case CalendarWeekRule.FirstFullWeek:
                    if (dayOfWeekForJan1 == 1)
                    {
                        offset = dayOfWeek - dayOfWeekForJan1;
                    }
                    else
                    {
                        offset = dayOfWeek + c_DAYS_PER_WEEK - dayOfWeekForJan1;
                    }

                    break;
            }
            retVal = (weekOfYear - 1) * c_DAYS_PER_WEEK + offset + 1;
            return retVal;
        }

 private void VerificationHelper(Calendar calendar, DateTime time, int expected, string errorno)
 {
     int actual = calendar.GetDayOfYear(time);
     Assert.Equal(expected, actual);
 }

        public static DateTime StartOfYear( this DateTime date, Calendar calendar )
        {
            Arg.NotNull( calendar, nameof( calendar ) );
            Contract.Ensures( calendar.GetYear( Contract.Result<DateTime>() ) == Contract.OldValue( calendar.GetYear( date ) ) );

            return date.AddDays( (double) ( -calendar.GetDayOfYear( date ) + 1 ) );
        }

        // This is copied from the generic implementation of GetWeekOfYearFullDays() in Calendar.cs.  The generic implementation is not good enough 
        // in the case of FristFullWeek and FirstFourDayWeek since it needs the data for B.C. year 1 near 0001/1/1.
        // We override the generic implementation to handle this special case.

        // Parameters 
        //
        internal static int InternalGetWeekOfYearFullDays(Calendar cal, DateTime time, int firstDayOfWeek, int fullDays, int daysOfMinYearMinusOne) { 
            int dayForJan1; 
            int offset;
            int day; 

            int dayOfYear = cal.GetDayOfYear(time) - 1; // Make the day of year to be 0-based, so that 1/1 is day 0.
            //
            // Calculate the number of days between the first day of year (1/1) and the first day of the week. 
            // This value will be a positive value from 0 ~ 6.  We call this value as "offset".
            // 
            // If offset is 0, it means that the 1/1 is the start of the first week. 
            //     Assume the first day of the week is Monday, it will look like this:
            //     Sun      Mon     Tue     Wed     Thu     Fri     Sat 
            //     12/31    1/1     1/2     1/3     1/4     1/5     1/6
            //              +--> First week starts here.
            //
            // If offset is 1, it means that the first day of the week is 1 day ahead of 1/1. 
            //     Assume the first day of the week is Monday, it will look like this:
            //     Sun      Mon     Tue     Wed     Thu     Fri     Sat 
            //     1/1      1/2     1/3     1/4     1/5     1/6     1/7 
            //              +--> First week starts here.
            // 
            // If offset is 2, it means that the first day of the week is 2 days ahead of 1/1.
            //     Assume the first day of the week is Monday, it will look like this:
            //     Sat      Sun     Mon     Tue     Wed     Thu     Fri     Sat
            //     1/1      1/2     1/3     1/4     1/5     1/6     1/7     1/8 
            //                      +--> First week starts here.
 
 

            // Day of week is 0-based. 
            // Get the day of week for 1/1.  This can be derived from the day of week of the target day.
            // Note that we can get a negative value.  It's ok since we are going to make it a positive value when calculating the offset.
            dayForJan1 = (int)cal.GetDayOfWeek(time) - (dayOfYear % 7);
 
            // Now, calucalte the offset.  Substract the first day of week from the dayForJan1.  And make it a positive value.
            offset = (firstDayOfWeek - dayForJan1 + 14) % 7; 
            if (offset != 0 && offset >= fullDays) 
            {
                // 
                // If the offset is greater than the value of fullDays, it means that
                // the first week of the year starts on the week where Jan/1 falls on.
                //
                offset -= 7; 
            }
            // 
            // Calculate the day of year for specified time by taking offset into account. 
            //
            day = dayOfYear - offset; 
            if (day >= 0) {
                //
                // If the day of year value is greater than zero, get the week of year.
                // 
                return (day/7 + 1);
            } 
            // 
            // Otherwise, the specified time falls on the week of previous year.
            // Note that it is not always week 52 or 53, because it depends on the calendar.  Different calendars have different number of days in a year. 
            //

            // Repeat the previous calculation logic using the previous year and calculate the week of year for the last day of previous year.
            int year = cal.GetYear(time); 
            if (year <= cal.GetYear(cal.MinSupportedDateTime)) {
                // This specified time is in 0001/1/1 ~ 0001/1/7. 
                dayOfYear = daysOfMinYearMinusOne; 
            } else {
                dayOfYear = cal.GetDaysInYear(year - 1); 
            }
            dayForJan1 = dayForJan1 - (dayOfYear % 7);
            // Now, calucalte the offset.  Substract the first day of week from the dayForJan1.  And make it a positive value.
            offset = (firstDayOfWeek - dayForJan1 + 14) % 7; 
            if (offset != 0 && offset >= fullDays)
            { 
                // 
                // If the offset is greater than the value of fullDays, it means that
                // the first week of the year starts on the week where Jan/1 falls on. 
                //
                offset -= 7;
            }
            // 
            // Calculate the day of year for specified time by taking offset into account.
            // 
            day = dayOfYear - offset; 
            return (day/7 + 1);
        } 

 internal static int InternalGetWeekOfYearFullDays(Calendar cal, DateTime time, int firstDayOfWeek, int fullDays, int daysOfMinYearMinusOne)
 {
     int daysInYear = cal.GetDayOfYear(time) - 1;
     int num = ((int) cal.GetDayOfWeek(time)) - (daysInYear % 7);
     int num2 = ((firstDayOfWeek - num) + 14) % 7;
     if ((num2 != 0) && (num2 >= fullDays))
     {
         num2 -= 7;
     }
     int num3 = daysInYear - num2;
     if (num3 < 0)
     {
         int year = cal.GetYear(time);
         if (year <= cal.GetYear(cal.MinSupportedDateTime))
         {
             daysInYear = daysOfMinYearMinusOne;
         }
         else
         {
             daysInYear = cal.GetDaysInYear(year - 1);
         }
         num -= daysInYear % 7;
         num2 = ((firstDayOfWeek - num) + 14) % 7;
         if ((num2 != 0) && (num2 >= fullDays))
         {
             num2 -= 7;
         }
         num3 = daysInYear - num2;
     }
     return ((num3 / 7) + 1);
 }