公历转为农历的函数

/// <summary>
    /// 公历转为农历的函数
    /// </summary>
    /// <param name="solarDateTime">公历日期</param>
    /// <returns>农历的日期</returns>
    static string SolarToChineseLunisolarDate(DateTime solarDateTime)
    {
        System.Globalization.ChineseLunisolarCalendar cal = new System.Globalization.ChineseLunisolarCalendar();

        int year = cal.GetYear(solarDateTime);
        int month = cal.GetMonth(solarDateTime);
        int day = cal.GetDayOfMonth(solarDateTime);
        int leapMonth = cal.GetLeapMonth(year);
        //return string.Format("农历{0}{1}（{2}）年{3}{4}月{5}{6}"
        //                    , "甲乙丙丁戊己庚辛壬癸"[(year - 4) % 10]
        //                    , "子丑寅卯辰巳午未申酉戌亥"[(year - 4) % 12]
        //                    , "鼠牛虎兔龙蛇马羊猴鸡狗猪"[(year - 4) % 12]
        //                    , month == leapMonth ? "闰" : ""
        //                    , "无正二三四五六七八九十冬腊"[leapMonth > 0 && leapMonth <= month ? month - 1 : month]
        //                    , "初十廿三"[day / 10]
        //                    , "日一二三四五六七八九"[day % 10]
        //                    );
        return string.Format("农历{0}月{1}{2}"
                            , "无正二三四五六七八九十冬腊"[leapMonth > 0 && leapMonth <= month ? month - 1 : month]
                            , "初十廿三"[day / 10]
                            , "日一二三四五六七八九"[day % 10]
                            );
    }