Flutter 阳历时间转农历
import 'package:intl/intl.dart';
class LunarCalendar {
//农历年
int year;
int month;
int day;
bool leap;
///中文月名称
static List chineseNumber = [
"一",
"二",
"三",
"四",
"五",
"六",
"七",
"八",
"九",
"十",
"十一",
"十二"
];
///中文日期格式
static DateFormat chineseDateFormat = new DateFormat("yyyy年MM月dd日");
///农历数据， 1901 ~ 2100 年之间正确
static List lunarInfo = [
0x04bd8,
0x04ae0,
0x0a570,
0x054d5,
0x0d260,
0x0d950,
0x16554,
0x056a0,
0x09ad0,
0x055d2,
0x04ae0,
0x0a5b6,
0x0a4d0,
0x0d250,
0x1d255,
0x0b540,
0x0d6a0,
0x0ada2,
0x095b0,
0x14977,
0x04970,
0x0a4b0,
0x0b4b5,
0x06a50,
0x06d40,
0x1ab54,
0x02b60,
0x09570,
0x052f2,
0x04970,
0x06566,
0x0d4a0,
0x0ea50,
0x06e95,
0x05ad0,
0x02b60,
0x186e3,
0x092e0,
0x1c8d7,
0x0c950,
0x0d4a0,
0x1d8a6,
0x0b550,
0x056a0,
0x1a5b4,
0x025d0,
0x092d0,
0x0d2b2,
0x0a950,
0x0b557,
0x06ca0,
0x0b550,
0x15355,
0x04da0,
0x0a5d0,
0x14573,
0x052d0,
0x0a9a8,
0x0e950,
0x06aa0,
0x0aea6,
0x0ab50,
0x04b60,
0x0aae4,
0x0a570,
0x05260,
0x0f263,
0x0d950,
0x05b57,
0x056a0,
0x096d0,
0x04dd5,
0x04ad0,
0x0a4d0,
0x0d4d4,
0x0d250,
0x0d558,
0x0b540,
0x0b5a0,
0x195a6,
0x095b0,
0x049b0,
0x0a974,
0x0a4b0,
0x0b27a,
0x06a50,
0x06d40,
0x0af46,
0x0ab60,
0x09570,
0x04af5,
0x04970,
0x064b0,
0x074a3,
0x0ea50,
0x06b58,
0x055c0,
0x0ab60,
0x096d5,
0x092e0,
0x0c960,
0x0d954,
0x0d4a0,
0x0da50,
0x07552,
0x056a0,
0x0abb7,
0x025d0,
0x092d0,
0x0cab5,
0x0a950,
0x0b4a0,
0x0baa4,
0x0ad50,
0x055d9,
0x04ba0,
0x0a5b0,
0x15176,
0x052b0,
0x0a930,
0x07954,
0x06aa0,
0x0ad50,
0x05b52,
0x04b60,
0x0a6e6,
0x0a4e0,
0x0d260,
0x0ea65,
0x0d530,
0x05aa0,
0x076a3,
0x096d0,
0x04bd7,
0x04ad0,
0x0a4d0,
0x1d0b6,
0x0d250,
0x0d520,
0x0dd45,
0x0b5a0,
0x056d0,
0x055b2,
0x049b0,
0x0a577,
0x0a4b0,
0x0aa50,
0x1b255,
0x06d20,
0x0ada0
];
// 传回农历 y年的总天数
static int yearDays(int y) {
int i, sum = 348;
for (i = 0x8000; i > 0x8; i >>= 1) {
if ((lunarInfo[y - 1900] & i) != 0) sum += 1;
}
return (sum + leapDays(y));
}
// 传回农历 y年闰月的天数
static int leapDays(int y) {
if (leapMonthM(y) != 0) {
if ((lunarInfo[y - 1900] & 0x10000) != 0)
return 30;
else
return 29;
} else
return 0;
}
// 传回农历 y年闰哪个月 1-12 , 没闰传回 0
static int leapMonthM(int y) {
print('$y');
return (lunarInfo[y - 1900] & 0xf);
}
// 传回农历 y年m月的总天数
static int monthDays(int y, int m) {
if ((lunarInfo[y - 1900] & (0x10000 >> m)) == 0)
return 29;
else
return 30;
}
// 传回农历 y年的生肖
String animalsYear() {
final List Animals = [
"鼠",
"牛",
"虎",
"兔",
"龙",
"蛇",
"马",
"羊",
"猴",
"鸡",
"狗",
"猪"
];
return Animals[(year - 4) % 12];
}
// 传入 月日的offset 传回干支, 0=甲子
static String cyclicalm(int num) {
final List Gan = ["甲", "乙", "丙", "丁", "戊", "己", "庚", "辛", "壬", "癸"];
final List Zhi = [
"子",
"丑",
"寅",
"卯",
"辰",
"巳",
"午",
"未",
"申",
"酉",
"戌",
"亥"
];
return (Gan[num % 10] + Zhi[num % 12]);
}
// 传入 offset 传回干支, 0=甲子
String cyclical() {
int num = year - 1900 + 36;
return (cyclicalm(num));
}
static String getChinaDayString(int day) {
List chineseTen = ["初", "十", "廿", "卅"];
int n = day % 10 == 0 ? 9 : day % 10 - 1;
if (day > 30) return "";
if (day == 10)
return "初十";
else
return chineseTen[day ~/ 10] + chineseNumber[n];
}
String getChinaMonthString() {
return chineseNumber[month - 1];
}
String toString() {
return "$year" +
"年" +
(leap ? "闰" : "") +
chineseNumber[month - 1] +
"月" +
getChinaDayString(day);
}
///使用指定日历日期构造一个农历日历
LunarCalendar(DateTime cal) {
int yearCyl, monCyl, dayCyl;
int leapMonth = 0;
DateTime baseDate = null;
try {
baseDate = chineseDateFormat.parse("1900年1月31日");
} catch (e) {}
// 求出和1900年1月31日相差的天数, 注意此处毫秒，除以86400000000
int offset =
((cal.microsecondsSinceEpoch - baseDate.microsecondsSinceEpoch) ~/
86400000000);
dayCyl = offset + 40;
monCyl = 14;
// 用offset减去每农历年的天数
// 计算当天是农历第几天
// i最终结果是农历的年份
// offset是当年的第几天
int iYear, daysOfYear = 0;
for (iYear = 1900; iYear < 2050 && offset > 0; iYear++) {
daysOfYear = yearDays(iYear);
offset -= daysOfYear;
monCyl += 12;
}
if (offset < 0) {
offset += daysOfYear;
iYear--;
monCyl -= 12;
}
// 农历年份
year = iYear;
yearCyl = iYear - 1864;
leapMonth = leapMonthM(iYear); // 闰哪个月,1-12
leap = false;
// 用当年的天数offset,逐个减去每月（农历）的天数，求出当天是本月的第几天
int iMonth, daysOfMonth = 0;
for (iMonth = 1; iMonth < 13 && offset > 0; iMonth++) {
// 闰月
if (leapMonth > 0 && iMonth == (leapMonth + 1) && !leap) {
--iMonth;
leap = true;
daysOfMonth = leapDays(year);
} else
daysOfMonth = monthDays(year, iMonth);
offset -= daysOfMonth;
// 解除闰月
if (leap && iMonth == (leapMonth + 1)) leap = false;
if (!leap) monCyl++;
}
// offset为0时，并且刚才计算的月份是闰月，要校正
if (offset == 0 && leapMonth > 0 && iMonth == leapMonth + 1) {
if (leap) {
leap = false;
} else {
leap = true;
--iMonth;
--monCyl;
}
}
// offset小于0时，也要校正
if (offset < 0) {
offset += daysOfMonth;
--iMonth;
--monCyl;
}
month = iMonth;
day = offset + 1;
}
使用：
LunarCalendar lunarCalendar = LunarCalendar(DateTime.now());
String time = '${lunarCalendar.getChinaMonthString()}月${LunarCalendar.getChinaDayString(lunarCalendar.day)}'