C# 获取农历日期

//C# 获取农历日期

///<summary>
/// 实例化一个 ChineseLunisolarCalendar
///</summary>
private static  ChineseLunisolarCalendar ChineseCalendar =new ChineseLunisolarCalendar();
 
///<summary>
/// 十天干
///</summary>
private static string[] tg = { "甲", "乙", "丙", "丁", "戊", "己", "庚", "辛", "壬", "癸" };
 
///<summary>
/// 十二地支
///</summary>
private static string[] dz = { "子", "丑", "寅", "卯", "辰", "巳", "午", "未", "申", "酉", "戌", "亥" };
 
///<summary>
/// 十二生肖
///</summary>
private static string[] sx = { "鼠", "牛", "虎", "免", "龙", "蛇", "马", "羊", "猴", "鸡", "狗", "猪" };
 
///<summary>
/// 返回农历天干地支年
///</summary>
///<param name="year">农历年</param>
///<return s></return s>
public static string GetLunisolarYear(int year)
{
    if (year >3)
    {
        int tgIndex = (year -4) %10;
        int dzIndex = (year -4) %12;
         
        return string.Concat(tg[tgIndex], dz[dzIndex], "[", sx[dzIndex], "]");
    }
     
    throw new ArgumentOutOfRangeException("无效的年份!");
}
 
///<summary>
/// 农历月
///</summary>
 
///<return s></return s>
private static string[] months = { "正", "二", "三", "四", "五", "六", "七", "八", "九", "十", "十一", "十二(腊)" };
 
///<summary>
/// 农历日
///</summary>
private static string[] days1 = { "初", "十", "廿", "三" };
///<summary>
/// 农历日
///</summary>
private static string[] days = { "一", "二", "三", "四", "五", "六", "七", "八", "九", "十" };
 
 
///<summary>
/// 返回农历月
///</summary>
///<param name="month">月份</param>
///<return s></return s>
public static string GetLunisolarMonth(int month)
{
    if (month <13 && month >0)
    {
        return  months[month -1];
    }
     
    throw  new ArgumentOutOfRangeException("无效的月份!");
}
 
///<summary>
/// 返回农历日
///</summary>
///<param name="day">天</param>
///<return s></return s>
public static string GetLunisolarDay(int day)
{
    if (day >0 && day <32)
    {
        if (day !=20 && day !=30)
        {
            return string.Concat(days1[(day -1) /10], days[(day -1) %10]);
        }
        else
        {
            return string.Concat(days[(day -1) /10], days1[1]);
         }
    }
     
    throw new ArgumentOutOfRangeException("无效的日!");
}
 
 
 
///<summary>
/// 根据公历获取农历日期
///</summary>
///<param name="datetime">公历日期</param>
///<return s></return s>
public static string GetChineseDateTime(DateTime datetime)
{
    int year = ChineseCalendar.GetYear(datetime);
    int month = ChineseCalendar.GetMonth(datetime);
    int day = ChineseCalendar.GetDayOfMonth(datetime);
    //获取闰月， 0 则表示没有闰月
    int leapMonth = ChineseCalendar.GetLeapMonth(year);
     
    bool isleap =false;
     
    if (leapMonth >0)
    {
        if (leapMonth == month)
        {
        //闰月
            isleap =true;
            month--;
        }
        else if (month > leapMonth)
        {
             month--;
        }
    }
     
    return string.Concat(GetLunisolarYear(year), "年", isleap ?"闰" : string.Empty, GetLunisolarMonth(month), "月", GetLunisolarDay(day));
}