.net 農曆計算方法

#region 農曆計算
public string ChineseTimeNow = "";
public string ForignTimeNow = "";
private static ChineseLunisolarCalendar calendar = new ChineseLunisolarCalendar();
private static string ChineseNumber = "〇一二三四五六七八九";
public const string CelestialStem = "甲乙丙丁戊己庚辛壬癸";
public const string TerrestrialBranch = "子醜寅卯辰巳午未申酉戌亥";
public static readonly string[] ChineseDayName = new string[] {
"初一","初二","初三","初四","初五","初六","初七","初八","初九","初十",
"十一","十二","十三","十四","十五","十六","十七","十八","十九","二十",
"廿一","廿二","廿三","廿四","廿五","廿六","廿七","廿八","廿九","三十"};
public static readonly string[] ChineseMonthName = new string[] { "正", "二", "三", "四", "五", "六", "七", "八", "九", "十", "十一", "十二" };


/// <summary>
/// 獲取一個公曆日期對應的完整的農曆日期
/// </summary>
/// <param name="time">一個公曆日期</param>
/// <returns>農曆日期</returns>
public string GetChineseDate(DateTime time)
{
string strY = GetYear(time);
string strM = GetMonth(time);
string strD = GetDay(time);
string strSB = GetStemBranch(time);
//string strDate = strY + "(" + strSB + ")年 " + strM + "月 " + strD;
string strDate = strSB + "年" + strM + "月" + strD;
return strDate;
}
/// <summary>
/// 獲取一個公曆日期的農曆干支紀年
/// </summary>
/// <param name="time">一個公曆日期</param>
/// <returns>農曆干支紀年</returns>
public string GetStemBranch(DateTime time)
{
int sexagenaryYear = calendar.GetSexagenaryYear(time);
string stemBranch = CelestialStem.Substring(sexagenaryYear % 10 - 1, 1) + TerrestrialBranch.Substring(sexagenaryYear % 12 - 1, 1);
return stemBranch;
}

/// <summary>
/// 獲取一個公曆日期的農曆年份
/// </summary>
/// <param name="time">一個公曆日期</param>
/// <returns>農曆年份</returns>
public string GetYear(DateTime time)
{
StringBuilder sb = new StringBuilder();
int year = calendar.GetYear(time);
int d;
do
{
d = year % 10;
sb.Insert(0, ChineseNumber[d]);
year = year / 10;
} while (year > 0);
return sb.ToString();
}

/// <summary>
/// 獲取一個公曆日期的農曆月份
/// </summary>
/// <param name="time">一個公曆日期</param>
/// <returns>農曆月份</returns>
public string GetMonth(DateTime time)
{
int month = calendar.GetMonth(time);
int year = calendar.GetYear(time);
int leap = 0;

//正月不可能閏月
for (int i = 3; i <= month; i++)
{
if (calendar.IsLeapMonth(year, i))
{
leap = i;
break; //一年中最多有一個閏月
}

}
if (leap > 0) month--;
return (leap == month + 1 ? "閏" : "") + ChineseMonthName[month - 1];
}


/// <summary>
/// 獲取一個公曆日期的農曆日
/// </summary>
/// <param name="time">一個公曆日期</param>
/// <returns>農曆日</returns>
public string GetDay(DateTime time)
{
return ChineseDayName[calendar.GetDayOfMonth(time) - 1];
}
#endregion