C# 计算农历日期方法（2021版）

解决问题

旧版农历获取方法报错，会有
到 2021年 m数组越界了 if (LunarData[m] < 4095)
此方法可以解决

主体代码

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", "惊蛰", "春分", "清明", "谷雨", "立夏", "小满", "芒种", "夏至", "小暑", "大暑", "立秋", "处暑", "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()
    {
        //公历节日
        gHoliday.Add("0101", "元旦");
        gHoliday.Add("0214", "情人节");
        gHoliday.Add("0305", "雷锋日");
        gHoliday.Add("0308", "妇女节");
        gHoliday.Add("0312", "植树节");
        gHoliday.Add("0315", "消费者权益日");
        gHoliday.Add("0401", "愚人节");
        gHoliday.Add("0501", "劳动节");
        gHoliday.Add("0504", "青年节");
        gHoliday.Add("0601", "儿童节");
        gHoliday.Add("0701", "建党节");
        gHoliday.Add("0801", "建军节");
        gHoliday.Add("0910", "教师节");
        gHoliday.Add("1001", "国庆节");
        gHoliday.Add("1224", "平安夜");
        gHoliday.Add("1225", "圣诞节");

        //农历节日
        nHoliday.Add("0101", "春节");
        nHoliday.Add("0115", "元宵节");
        nHoliday.Add("0505", "端午节");
        nHoliday.Add("0815", "中秋节");
        nHoliday.Add("0909", "重阳节");
        nHoliday.Add("1208", "腊八节");
    }

    /// <summary>
    /// 获取农历
    /// </summary>
    /// <param name="dt"></param>
    /// <returns></returns>
    public static string GetChinaDate(DateTime dt)
    {
        if (dt > china.MaxSupportedDateTime || dt < china.MinSupportedDateTime)
        {
            //日期范围：1901 年 2 月 19 日 - 2101 年 1 月 28 日
            throw new Exception(string.Format("日期超出范围！必须在{0}到{1}之间！", 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);
        if (strHoliday != "")
        {
            str += " " + strHoliday;
        }
        string strChinaHoliday = GetChinaHoliday(dt);
        if (strChinaHoliday != "")
        {
            str += " " + strChinaHoliday;
        }

        return str;
    }

    /// <summary>
    /// 获取农历年份
    /// </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 = " 子丑寅卯辰巳午未申酉戌亥";
        string yearSX = " 鼠牛虎兔龙蛇马羊猴鸡狗猪";
        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>
    /// 获取农历月份
    /// </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 ? "闰" : "";
        if (iMonth <= 10)
        {
            strMonth += szText.Substring(iMonth - 1, 1);
        }
        else if (iMonth == 11)
        {
            strMonth += "十一";
        }
        else
        {
            strMonth += "腊";
        }
        return strMonth + "月";
    }

    /// <summary>
    /// 获取农历日期
    /// </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;
    }

    /// <summary>
    /// 获取节气
    /// </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>
    /// 获取公历节日
    /// </summary>
    /// <param name="dt"></param>
    /// <returns></returns>
    public static string GetHoliday(DateTime dt)
    {
        string strReturn = "";
        object g = gHoliday[dt.Month.ToString("00") + dt.Day.ToString("00")];
        if (g != null)
        {
            strReturn = g.ToString();
        }

        return strReturn;
    }

    /// <summary>
    /// 获取农历节日
    /// </summary>
    /// <param name="dt"></param>
    /// <returns></returns>
    public static string GetChinaHoliday(DateTime dt)
    {
        string strReturn = "";
        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)
            {
                if (strReturn == "")
                {
                    strReturn = n.ToString();
                }
                else
                {
                    strReturn += " " + n.ToString();
                }
            }
        }

        return strReturn;
    }
}

调用方法：

ChinaDate.GetChinaDate(DateTime dt) //获取农历日期

ChinaDate.GetYear(DateTime dt) //获取农历年份（包含天干地支和生肖信息）

ChinaDate.GetMonth(DateTime dt) //获取农历月份

ChinaDate.GetDay(DateTime dt) //获取农历日期

ChinaDate.GetSolarTerm(DateTime dt) //获取节气

ChinaDate.GetHoliday(DateTime dt) //获取公历节日