【微信小程序】获取农历及星期

在微信小程序的util.js中，有这样一个工具方法

const formatTime = date => {
  const year = date.getFullYear()
  const month = date.getMonth() + 1
  const day = date.getDate()
  const hour = date.getHours()
  const minute = date.getMinutes()
  const second = date.getSeconds()

  return [year, month, day].map(formatNumber).join('/') + ' ' + [hour, minute, second].map(formatNumber).join(':')
}

该方法可以获取到当前日期时间，但是，过生日的时候很多人都用农历，那么如何获得农历呢，微信小程序并没有提供相关的API可供调用，搜索网络也找不到相关方法，最多只能找到javascript、java版本的
于是找了一个java版本的代码进行了简单改造，最终实现获取农历（月和日）的功能

一、获取农历

/**
   * @ref:https://www.iteye.com/blog/lixor-1190599
   */
  getLunarDate: function() {
    var self = this;
    var yearCyl,monCyl,dayCyl;
    var leapMonth = 0;
    var date = new Date('1900/1/31');
    var curDate =new Date();
    // 求出和1900年1月31日相差的天数
    var offset = parseInt( (curDate.getTime() - date.getTime()) / 86400000 );
    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
    var iYear, daysOfYear = 0;
    for (iYear = 1900; iYear < 2050 && offset > 0; iYear++) {
      daysOfYear = self.yearDays(iYear);
      offset -= daysOfYear;
      monCyl += 12;
    }
    if (offset < 0) {
      offset += daysOfYear;
      iYear--;
      monCyl -= 12;
    }
    yearCyl = iYear - 1864;
    leapMonth = self.leapMonth(iYear); // 闰哪个月,1-12
    var leap = false; // 默认值
    // 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
    var iMonth, daysOfMonth = 0;
    for (iMonth = 1; iMonth < 13 && offset > 0; iMonth++) {
      // 闰月
      if (leapMonth > 0 && iMonth == (leapMonth + 1) && !leap) {
        --iMonth;
        leap = true;
        daysOfMonth = self.leapDays(iYear);
      } else
        daysOfMonth = self.monthDays(iYear, 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;
    }
    var newday = self.getChinaDayString(offset + 1);
    var newmonth = self.data.chineseNumber[iMonth - 1];
    self.setData({
      lunarDate: newmonth + '月' + newday
    })
    console.log(newmonth + '月' + newday);
  },
  

工具方法

   yearDays: function (y) {
    var self = this;
    var i, sum = 348;
    for (i = 0x8000; i > 0x8; i >>= 1) {
      if ((self.data.lunarInfo[y - 1900] & i) != 0)
        sum += 1;
    }
    return (sum + self.leapDays(y));
  },
  leapDays: function(y){
    var self = this;
    if (self.leapMonth(y) != 0) {
      if ((self.data.lunarInfo[y - 1900] & 0x10000) != 0)
        return 30;
      else
        return 29;
    } else
      return 0;
  },
  leapMonth:function(y) {
    var self = this;
    return self.data.lunarInfo[y - 1900] & 0xf;
  },
  monthDays:function(y,m){
    if ((this.data.lunarInfo[y - 1900] & (0x10000 >> m)) == 0)
      return 29;
    else
      return 30;
  },
  getChinaDayString:function(day){
  	var self = this;
    var chineseTen = [ "初", "十", "廿", "卅"];
    var n = day % 10 == 0 ? 9 : day % 10 - 1;
    if (day > 30)
      return "";
    if (day == 10)
      return "初十";
    else
     return chineseTen[parseInt(day/10)] + self.data.chineseNumber[n];
  }

data值

const app = getApp()
var util = require('../../utils/util.js')

Page({
	data: {
    	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
    ],
    	chineseNumber:[
      "一", "二", "三", "四", "五", "六", "七", "八", "九", "十", "冬", "十二"
    ],
    	week: util.getWeekByDate(new Date()),
    	lunarDate:'',
      },
  })

最终效果如图（冬月初十）

PS：上效果图是我正在开发的一款小程序，各位看官如果有空可扫码体验一下，互相学习交流

二、获取星期

封装了获取星期的方法，参考微信小程序-获取日期并计算星期几，此方法放在了util.js中，可直接调用

const getWeekByDate = dates => {
  let show_day = new Array('周日', '周一', '周二', '周三', '周四', '周五', '周六');
  let date = new Date(dates);
  date.setDate(date.getDate());
  let day = date.getDay();
  return show_day[day];
}
module.exports = {
  getWeekByDate: getWeekByDate
}