網站上顯示農曆及陽曆節日

把陽曆日期轉換為農曆用到的函數為ChinaDate.ConvertToNongLi(DateTime.Now);

得到節日的函數為 ChinaDate.GetFestival(DateTime.Now);

代碼：

using System.Globalization;using System.Collections;using System;namespace NetWeb2011.Common{    public static class ChinaDate    {        private static ChineseLunisolarCalendar china = new ChineseLunisolarCalendar();        private static Hashtable gHoliday = new Hashtable();        private static Hashtable nHoliday = new Hashtable();        private static string[] JQ = { "小寒", "大寒", "立春", "雨水", "驚蟄", "春分", "清明", "穀雨", "立夏", "小滿", "芒種", "夏至", "小暑", "大暑", "立秋", "處暑", "白露", "秋分", "寒露", "霜降", "立冬", "小雪", "大雪", "冬至" };        private static int[] JQData = { 0, 21208, 43467, 63836, 85337, 107014, 128867, 150921, 173149, 195551, 218072, 240693, 263343, 285989, 308563, 331033, 353350, 375494, 397447, 419210, 440795, 462224, 483532, 504758 };        static ChinaDate()        {            //西曆節日            gHoliday.Add("0101", "元旦");            gHoliday.Add("0214", "情人節");            gHoliday.Add("0305", "雷鋒日");            gHoliday.Add("0308", "婦女節");            gHoliday.Add("0312", "植樹節");            gHoliday.Add("0315", "消費者權益日");            gHoliday.Add("0401", "愚人節");            gHoliday.Add("0405", "清明節");            gHoliday.Add("0501", "勞動節");            gHoliday.Add("0504", "青年節");            gHoliday.Add("0601", "兒童節");            gHoliday.Add("0701", "建黨節");            gHoliday.Add("0801", "建軍節");            gHoliday.Add("0910", "教師節");            gHoliday.Add("1001", "國慶節");            gHoliday.Add("1031", "萬聖節");            gHoliday.Add("1224", "平安夜");            gHoliday.Add("1225", "聖誕節");            //農曆節日            nHoliday.Add("0101", "春節");            nHoliday.Add("0115", "元宵節");            nHoliday.Add("0505", "端午節");            nHoliday.Add("0815", "中秋節");            nHoliday.Add("0909", "重陽節");            nHoliday.Add("1208", "臘八節");            nHoliday.Add("1230", "大年三十");        }        /// <summary>        /// 擷取農曆        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string GetChinaDate(DateTime dt)        {            if (dt > china.MaxSupportedDateTime || dt < china.MinSupportedDateTime)            {                //日期範圍：1901 年 2 月 19 日 - 2101 年 1 月 28 日                throw new Exception(string.Format("日期超出範圍！必須在{0}到{1}之間！", china.MinSupportedDateTime.ToString("yyyy-MM-dd"), china.MaxSupportedDateTime.ToString("yyyy-MM-dd")));            }            string str = string.Format("{0} {1}{2}", GetYear(dt), GetMonth(dt), GetDay(dt));            string strJQ = GetSolarTerm(dt);            if (strJQ != "")            {                str += " (" + strJQ + ")";            }            string[] strHoliday = GetHoliday(dt, 0);            if (strHoliday != null)            {                str += " " + strHoliday;            }            string[] strChinaHoliday = GetChinaHoliday(dt, 0);            if (strChinaHoliday != null)            {                str += " " + strChinaHoliday;            }            return str;        }        /// <summary>        /// 擷取農曆年份        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string GetYear(DateTime dt)        {            int yearIndex = china.GetSexagenaryYear(dt);            string yearTG = " 甲乙丙丁戊己庚辛壬癸";            string yearDZ = " 子醜寅卯辰巳午未申酉戌亥";            string yearSX = " 鼠牛虎兔龍蛇馬羊猴雞狗豬";            int year = china.GetYear(dt);            int yTG = china.GetCelestialStem(yearIndex);            int yDZ = china.GetTerrestrialBranch(yearIndex);            string str = string.Format("[{1}]{2}{3}{0}", year, yearSX[yDZ], yearTG[yTG], yearDZ[yDZ]);            return str;        }        /// <summary>        /// 得到西曆所對應的農曆年        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string GetChinaYear(DateTime dt)        {            return china.GetYear(dt).ToString();        }        /// <summary>        /// 擷取農曆月份        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string GetMonth(DateTime dt)        {            int year = china.GetYear(dt);            int iMonth = china.GetMonth(dt);            int leapMonth = china.GetLeapMonth(year);            bool isLeapMonth = iMonth == leapMonth;            if (leapMonth != 0 && iMonth >= leapMonth)            {                iMonth--;            }            string szText = "正二三四五六七八九十";            string strMonth = isLeapMonth ? "閏" : "";            if (iMonth <= 10)            {                strMonth = "";                strMonth = strMonth + szText.Substring(iMonth - 1, 1);            }            else if (iMonth == 11)            {                strMonth = "十一";            }            else            {                strMonth = "臘";            }            return strMonth + "月";        }        /// <summary>        /// 擷取農曆日期        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string GetDay(DateTime dt)        {            int iDay = china.GetDayOfMonth(dt);            string szText1 = "初十廿三";            string szText2 = "一二三四五六七八九十";            string strDay;            if (iDay == 20)            {                strDay = "二十";            }            else if (iDay == 30)            {                strDay = "三十";            }            else            {                strDay = szText1.Substring((iDay - 1) / 10, 1);                strDay = strDay + szText2.Substring((iDay - 1) % 10, 1);            }            return strDay;        }        private static string GetNongLiDay(string str)        {            string ret = string.Empty;            ret += ConvertNongliToDigital(str.Substring(0, 1), 0);            ret += ConvertNongliToDigital(str.Substring(1, 1), 1);            return ret;        }        private static string GetNongLiMonth(string str)        {            string ret = string.Empty;            if (str.Length == 2) //是 十月 還是 十一月            {                ret += ConvertMonthToDigital(str.Substring(0, 1));                ret += ConvertMonthToDigital(str.Substring(1, 1));            }            else if (str.Length == 3)            {                ret += ConvertMonthToDigital(str.Substring(0, 2));            }            return ret;        }        /// <summary>        /// 把漢字月轉換成對應的數字        /// </summary>        /// <param name="nonglimonth"></param>        /// <returns></returns>        private static string ConvertMonthToDigital(string nonglimonth)        {            string ret = string.Empty;            switch (nonglimonth)            {                case "一": ret = "1";                    break;                case "二": ret = "2";                    break;                case "三": ret = "3";                    break;                case "四": ret = "4";                    break;                case "五": ret = "5";                    break;                case "六": ret = "6";                    break;                case "七": ret = "7";                    break;                case "八": ret = "8";                    break;                case "九": ret = "9";                    break;                case "十":                    ret = "10";                    break;                case "十一":                    ret = "11";                    break;                case "十二":                    ret = "12";                    break;                case "正":                    ret = "1";                    break;                case "臘":                    ret = "12";                    break;            }            return ret;        }        /// <summary>        /// 把漢字日轉換成對應的數字，first，是用來區別十這個漢字，是在第一個位置還是在別的位置上        /// </summary>        /// <param name="nongli"></param>        /// <param name="first"></param>        /// <returns></returns>        private static string ConvertNongliToDigital(string nongli, int first)        {            string ret = string.Empty;            switch (nongli)            {                case "一": ret = "1";                    break;                case "二": ret = "2";                    break;                case "三": ret = "3";                    break;                case "四": ret = "4";                    break;                case "五": ret = "5";                    break;                case "六": ret = "6";                    break;                case "七": ret = "7";                    break;                case "八": ret = "8";                    break;                case "九": ret = "9";                    break;                case "十":                    if (first == 1)                    {                        ret = "0";                    }                    else ret = "1";                    break;                case "初": ret = "0";                    break;                case "廿": ret = "2";                    break;            }            return ret;        }        /// <summary>        /// 擷取節氣        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string GetSolarTerm(DateTime dt)        {            DateTime dtBase = new DateTime(1900, 1, 6, 2, 5, 0);            DateTime dtNew;            double num;            int y;            string strReturn = "";            y = dt.Year;            for (int i = 1; i <= 24; i++)            {                num = 525948.76 * (y - 1900) + JQData[i - 1];                dtNew = dtBase.AddMinutes(num);                if (dtNew.DayOfYear == dt.DayOfYear)                {                    strReturn = JQ[i - 1];                }            }            return strReturn;        }        /// <summary>        /// 擷取西曆節日        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string[] GetHoliday(DateTime dt, int next) //next為0表示當前月，next為1表示下個月        {            string strReturn = "";            object g = null;            if (next == 0)            {                g = gHoliday[dt.Month.ToString("00") + dt.Day.ToString("00")];            }            if (g != null)            {                strReturn = g.ToString();                return new string[] { dt.Month.ToString("00") + dt.Day.ToString("00"), g.ToString() };            }            else            {                string first = string.Empty;                int day = 0;//當前多少號                if (next == 0)                {                    first = dt.Month.ToString("00");                    day = dt.Day; //當前多少號                }                else                {                    dt = dt.AddMonths(next);                    first = dt.Month.ToString("00");                }                day++;                for (int i = day; i <= 31; i++)                {                    object festival = gHoliday[first + i.ToString("00")];                    if (festival != null)                    {                        string[] ret = { first + i.ToString("00"), festival.ToString() }; //當前當月的離今天最近的一個節日                        return ret;                    }                }            }            return null;        }        /// <summary>        ///  擷取農曆節日        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string[] GetChinaHoliday(DateTime dt, int next) //next表示是否是下一個月        {            string strReturn = string.Empty;            int year = china.GetYear(dt);            int iMonth = china.GetMonth(dt);            int leapMonth = china.GetLeapMonth(year);            int iDay = china.GetDayOfMonth(dt);            if (china.GetDayOfYear(dt) == china.GetDaysInYear(year))            {                strReturn = "除夕";            }            else if (leapMonth != iMonth)            {                if (leapMonth != 0 && iMonth >= leapMonth)                {                    iMonth--;                }                object n = nHoliday[iMonth.ToString("00") + iDay.ToString("00")];                if (n != null)                {                    string[] ret = { iMonth.ToString("00") + iDay.ToString("00"), n.ToString() };                    return ret;                }                else  //該日期沒有節日                {                    if (next != 0)                    {                        iDay = 0;                        iMonth += next;                    }                    for (int i = iDay; i <= 31; i++)                    {                        object festival = nHoliday[iMonth.ToString("00") + i.ToString("00")];                        if (festival != null)                        {                            string[] ret = { iMonth.ToString("00") + i.ToString("00"), festival.ToString() };                            return ret;                        }                    }                }            }            if (strReturn != string.Empty)            {                return new string[] { "1230", "除夕" };            }            return null;        }        /// <summary>        /// 把陽曆轉成農曆        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static DateTime ConvertToNongLi(DateTime dt)        {            string year = ChinaDate.GetChinaYear(dt);            string month = ChinaDate.GetNongLiMonth(ChinaDate.GetMonth(dt));            string day = ChinaDate.GetNongLiDay(ChinaDate.GetDay(dt));            DateTime dtnongli = DateTime.Parse(year + "-" + month + "-" + day);            return dtnongli;        }        /// <summary>        /// 得到節日，沒有節日的話，就返回empty        /// </summary>        /// <param name="dt"></param>        /// <returns></returns>        public static string GetFestival(DateTime dt)        {            try            {                string currentfestival = string.Empty;                string nonglidate = string.Empty;                string gonglidate = string.Empty;                int distance = 0;                int basemonth = 0;                string[] gongli = ChinaDate.GetHoliday(dt, basemonth);//西曆節日                string[] nongli = ChinaDate.GetChinaHoliday(dt, basemonth);//農曆節日                bool festival = true; //是否這個月內有節日                DateTime dtGongli = dt;                DateTime dtNongli = dt;                if (gongli == null && nongli == null) //如果同時為空白，就取下個月的                {                    basemonth++;                    gongli = ChinaDate.GetHoliday(dt, basemonth);//西曆節日                    nongli = ChinaDate.GetChinaHoliday(dt, basemonth);//農曆節日                }                //dt = dt.AddMonths(basemonth);                if (gongli != null)                {                    DateTime riqi = DateTime.Parse(dt.Year.ToString() + "-" + gongli[0].Substring(0, 2) + "-" + gongli[0].Substring(2, 2));                    dtGongli = ConvertToNongLi(riqi);                }                if (nongli != null)                {                    dtNongli = DateTime.Parse(ChinaDate.GetChinaYear(dt) + "-" + nongli[0].Substring(0, 2) + "-" + nongli[0].Substring(2, 2));                }                System.Text.StringBuilder today = new System.Text.StringBuilder();                //today.Append(DateTime.Now.ToString("yyyy-MM-dd") + " " + DateTime.Now.ToString("ddd", new System.Globalization.CultureInfo("zh-cn")) + "  ");                if (gongli != null && nongli != null)                {                    TimeSpan ts = dtGongli - dtNongli;                    if (ts.Days < 0)// 西曆的節日更近 把兩個日期都轉換成西曆進行比較                    {                        currentfestival = gongli[1];                        gonglidate = gongli[0];                        TimeSpan tsDay = dtGongli - ConvertToNongLi(dt);                        distance = tsDay.Days;                    }                    else                    {                        ts = dtNongli - dtGongli;                        currentfestival = nongli[1];                        TimeSpan tsDay = dtNongli - ConvertToNongLi(dt);                        distance = tsDay.Days;                    }                }                else if (gongli != null)                {                    currentfestival = gongli[1];                    DateTime dtfestival = ConvertToNongLi(DateTime.Parse(ChinaDate.GetChinaYear(dt) + "-" + gongli[0].Substring(0, 2) + "-" + gongli[0].Substring(2, 2)));                    TimeSpan tsDay = dtfestival - ConvertToNongLi(dt);                    distance = tsDay.Days;                }                else if (nongli != null)                {                    currentfestival = nongli[1];                    distance = int.Parse(nongli[0].Substring(2, 2)) - ConvertToNongLi(dt).Day;                }                else festival = false;                //today.Append("農曆" + ChinaDate.GetMonth(dt) + ChinaDate.GetDay(dt));                if (festival)                {                    if (distance > 0)                        today.Append(" 離<font color='red'>" + currentfestival + "</font>還有<font color='red'>" + distance + "</font>天   ");                    else today.Append(" 今天是 <font color='red'>" + currentfestival + "</font>   ");                }                //else today.Append("  ");                return today.ToString();            }            catch            {                return string.Empty;            }        }    }}