Monthly由来

最近在做关于智能财税的项目，大量用到了账期相关的数据操作。项目已有两年历史了，对于账期数据，前辈们用的是DateTime数据类型，即每个月的最后一天就是账期。而用DateTime来表达账期数据，确实让我人很困惑：

1. 概念不统一：
   DateTime是时间类型，而账期只跟年月相关，DateTime用在这里确实有点杀鸡用了宰牛刀，而且给人的理解和沟通造成了额外的误解。
2. 格式不统一：
   为了在数据传输和存储中达到数据的统一性，需要大量的字符串与日期的转换、日期格式的转换。
3. 浪费性能：
   DateTime的精确度是可以到毫秒级的，而我们的账期数据只需要精确到月，如：2018年1月账期。 所以DateTime是很影响运算性能和存储空间的。
4. 操作异常：
   由于账期是取月末日期，所以对每次接收了账期参数都要取月末值，以确保数据的准确性。而在实际开发中，任何一个疏忽都会引发表达偏差。

Monthly简介

Monthly是一个跟Datetime类似的，与月份相关的数据类型，适用于表达年月数据，如账单、账期、月刊等信息。

Monthly源码

using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text.RegularExpressions;namespace System
{/// <summary>/// 与月份相关的对象，如账单、账期、月刊、月报等/// </summary>[Serializable][StructLayout(LayoutKind.Auto)]public struct Monthly : IComparable<Monthly>, IEquatable<Monthly>{private int _year;private int _month;#region Property/// <summary>///  获取当前实例的年/// </summary>public int Year => _year;/// <summary>///  获取当前实例的月/// </summary>public int Month => _month;/// <summary>/// 获取当前实例的年月标记值，如2018年1月记为 : 201801/// </summary>public int Dot => this._year * 100 + this._month;/// <summary>/// 获取当前实例从公元零年一月开始的月份累计值/// </summary>public int Tickes => this._year * 12 + this._month;/// <summary>///  获取当前实例所在的季度/// </summary>public int Quarter => (this._month - 1) / 3 + 1;#endregion#region Ctor/// <summary>///  以指定的年和月初始化Monthly实例。/// </summary>/// <param name="year"> 年（0 到 9999）</param>/// <param name="month"> 月（1 到 12）</param>public Monthly(int year, int month){CheckYear(year);CheckMonth(month);this._year = year;this._month = month;}/// <summary>/// 获取以当前时间点为依据的新实例/// </summary>public static Monthly Current => new Monthly() { _year = DateTime.Now.Year, _month = DateTime.Now.Month };/// <summary>/// 获取当前时间点的上月为依据的新实例/// </summary>public Monthly Previous => Monthly.fromTickes(this.Tickes - 1);/// <summary>/// 获取当前时间点的下月为依据的新实例/// </summary>public Monthly Next => Monthly.fromTickes(this.Tickes + 1);/// <summary>/// 获取当前年份的一月为依据的新实例  /// </summary>public Monthly First => new Monthly() { _year = this._year, _month = 1 };/// <summary>/// 获取当前年份的十二月为依据的新实例/// </summary>public Monthly Last => new Monthly() { _year = this._year, _month = 12 };/// <summary>/// 获取Monthly的最小值实例/// </summary>public static Monthly MinValue => new Monthly() { _year = 0, _month = 1 };/// <summary>/// 获取Monthly的最大值实例/// </summary>public static Monthly MaxValue => new Monthly() { _year = 9999, _month = 12 };#endregion#region Methodprivate static int yearOfDot(int dot) => dot / 100;private static int monthOfDot(int dot) => dot % 100;/// <summary>/// 获取当前实例的年月标记值，如2018年1月记为 : 201801/// </summary>/// <returns></returns>public int ToDot() => this.Dot;/// <summary>/// 以当前实例与years的和值为依据创建一个新实例/// </summary>public Monthly AddYears(int years) => Monthly.FromTickes(this.Tickes + years * 12);/// <summary>/// 以当前实例与months的和值为依据创建一个新实例/// </summary>public Monthly AddMonths(int months) => Monthly.FromTickes(this.Tickes + months);/// <summary>/// 判断当前实例的值与给定实例的值是否相等/// </summary>public bool Equals(Monthly other) => this.Tickes == other.Tickes;/// <summary>/// 获取当前实例与给定实例的月份差值/// </summary>public int SpanMonths(Monthly other) => this - other;/// <summary>/// 获取当前实例与DateTime实例的月份差值/// </summary>public int SpanMonths(DateTime date) => this.Tickes - date.Year * 12 - date.Month;/// <summary>/// 获取当前实例与给定实例的大小比较的结果标识/// </summary>/// <param name="other"></param>/// <returns>-1:小于other实例值 ； 0 等于other实例值 ； 1：大于other实例值</returns>public int CompareTo(Monthly other){if (this.Tickes < other.Tickes) return -1;if (this.Tickes > other.Tickes) return 1;else return 0;}/// <summary>/// 以年月标记值创建一个Monthly新实例/// </summary>/// <param name="dot">格式：201801</param>/// <returns></returns>public static Monthly FromDot(int dot){var year = yearOfDot(dot);var month = monthOfDot(dot);if (year < 0 || year > 9999 || month < 1 || month > 12)throw new ArgumentOutOfRangeException("dot", dot, "Please enter correct dot format such as \'201801\'.");return new Monthly{_year = yearOfDot(dot),_month = monthOfDot(dot)};}private static Monthly fromTickes(int tickes){return new Monthly{_year = (tickes - 1) / 12,_month = tickes % 12 == 0 ? 12 : tickes % 12};}/// <summary>/// 以年月累计值创建一个Monthly新实例/// </summary>/// <param name="tickes">以公元零年一月为起点的月份计数值（1-120000）</param>public static Monthly FromTickes(int tickes){if (tickes < 1 || tickes > 120000)throw new ArgumentOutOfRangeException("tickes", tickes, "The tickes must beteen 1 and 120000 .");return fromTickes(tickes);}/// <summary>/// 以DateTime实例创建一个Monthly新实例/// </summary>public static Monthly FromDate(DateTime time) => new Monthly() { _year = time.Year, _month = time.Month };/// <summary>/// 以诸如"2018/01"格式的字符串创建一个Monthly新实例/// </summary>/// <param name="s">"2018/01"格式的字符串</param>/// <param name="spliter">分隔符</param>public static Monthly FromString(string s){if (string.IsNullOrEmpty(s))throw new Exception("The parameter cannot be null or empty.");var nums = Regex.Matches(s, "[0-9]+");if (nums.Count == 0)throw new Exception("Please give the correct parameters, such as '2018/01' .");if (nums.Count == 1)return new Monthly(0, Convert.ToInt32(nums[0].ToString().TrimStart('0')));elsereturn new Monthly(Convert.ToInt32(nums[0].ToString().TrimStart('0')), Convert.ToInt32(nums[1].ToString().TrimStart('0')));}/// <summary>/// 获取一段时间内的Monthly数轴(包含开始与结束月份)/// </summary>/// <param name="from">开始月份</param>/// <param name="to">结束月份</param>/// <returns></returns>public static List<Monthly> Axis(Monthly from, Monthly to){var result = new List<Monthly>();var span = from - to;var len = (span ^ (span >> 31)) - (span >> 31) + 1;for (int i = 0; i < len; i++){if (span > 0) result.Add(from - i);else result.Add(from + i);}return result;}/// <summary>/// 获取给定时间段内的Monthly集合(包含开始与结束月份)/// </summary>/// <param name="from">开始月份</param>/// <param name="to">结束月份</param>/// <returns></returns>public static List<Monthly> Axis(int from, int to){return Axis(Monthly.FromDot(from), Monthly.FromDot(to));}/// <summary>/// 检查year的合法性/// </summary>private static void CheckYear(int year){if (year < 0 || year > 9999)throw new ArgumentOutOfRangeException("year", year, "The year must beteen 0 and 9999 .");}/// <summary>/// 检查month的合法性/// </summary>private static void CheckMonth(int month){if (month < 1 || month > 12)throw new ArgumentOutOfRangeException("month", month, "The month must beteen 1 and 12 .");}#endregion#region Operator/// <summary>/// 以给定实例与months的和值创建一个新实例/// </summary>/// <param name="months">月分数</param>public static Monthly operator +(Monthly m, int months) => FromTickes(m.Tickes + months);/// <summary>/// 以给定实例与months的差值创建一个新实例/// </summary>/// <param name="months">月分数</param>public static Monthly operator -(Monthly m, int months) => FromTickes(m.Tickes - months);/// <summary>/// 获取当前实例与给定实例的月份差值/// </summary>public static int operator -(Monthly m1, Monthly m2) => m1.Tickes - m2.Tickes;/// <summary>///获取当前实例与DateTime实例的月份差值/// </summary>public static int operator -(Monthly m, DateTime d) => m.SpanMonths(d);public static Monthly operator ++(Monthly m) => m + 1;public static Monthly operator --(Monthly m) => m - 1;/// <summary>///判断m1是否等于m2/// </summary>public static bool operator ==(Monthly m1, Monthly m2) => m1.Tickes == m2.Tickes;/// <summary>/// 判断m1是否不等于m2/// </summary>public static bool operator !=(Monthly m1, Monthly m2) => m1.Tickes != m2.Tickes;/// <summary>/// 判断m1是否小于m2/// </summary>public static bool operator <(Monthly m1, Monthly m2) => m1.Tickes < m2.Tickes;/// <summary>/// 判断m1是否大于m2/// </summary>public static bool operator >(Monthly m1, Monthly m2){return m1.Tickes > m2.Tickes; ;}/// <summary>/// 判断m1是否小于等于m2/// </summary>public static bool operator <=(Monthly m1, Monthly m2){return m1.Tickes <= m2.Tickes; ;}/// <summary>/// 判断m1是否大于等于m2/// </summary>public static bool operator >=(Monthly m1, Monthly m2){return m1.Tickes >= m2.Tickes; ;}/// <summary>/// 以年月标识的Monthly实例/// </summary>/// <param name="dot">格式：201801</param>public static implicit operator Monthly(int dot){return Monthly.FromDot(dot);}#endregion#region Override/// <summary>/// 获取包含"Y、y、M、m"字符格式的自定义Monthly字符串/// </summary>/// <param name="format">/// 如：yyyy/mm ; yy/mm ; yyyy年mm月 ;YYYY-Mm.../// 不区分大小写/// </param>/// <returns></returns>public string ToString(string format = "yyyy/mm"){return Format(this, format);}/// <summary>/// 判断当前实例的值与给定实例的转换值是否相等/// </summary>public override bool Equals(object obj){if (obj is null) throw new ArgumentNullException("obj", "The parameter cannot be null.");if (obj is Monthly) return this == (Monthly)obj;if (obj is DateTime) return this == Monthly.FromDate((DateTime)obj);throw new ArgumentException("The parameter must be System.DateTime type or System.Monthly type .", "obj");}public override int GetHashCode(){Int64 ticks = Tickes;return unchecked((int)ticks) ^ (int)(ticks >> 32);}private static string Format(Monthly m, string format){string _y = m.Year.ToString();string _m = m.Month.ToString();format = format.ToLower();if (!(format.Contains("yyyy") || format.Contains("yyyy")) && !(format.Contains("mm") || format.Contains("m")))throw new ArgumentException("The format expression error. ", nameof(format));if (format.Contains("yyyy"))format = format.Replace("yyyy", m.Year < 10 ? $"0{_y}" : _y);else if (format.Contains("yy"))format = format.Replace("yy", m.Year < 10 ? $"0{_y}" : _y.PadLeft(4, '0').Substring(2));if (format.Contains("mm"))format = format.Replace("mm", m.Month < 10 ? $"0{_m}" : _m);else if (format.Contains("m"))format = format.Replace("m", _m.TrimStart('0'));return format;}#endregion}
}

测试

using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;namespace Pilipa.Utility.Test
{[TestClass]public class MonthlyTest{[TestMethod]public void TestProps(){var tar = DateTime.Now;Monthly plan = Monthly.FromDate(tar);Assert.AreEqual(Monthly.Current, new Monthly(tar.Year, tar.Month));Assert.AreEqual(plan.Year, tar.Year);Assert.AreEqual(plan.Month, tar.Month);Assert.AreEqual(plan.Dot, tar.Year * 100 + tar.Month);Assert.AreEqual(plan.Tickes, tar.Year * 12 + tar.Month);Assert.AreEqual(plan.First.ToDot(), tar.Year * 100 + 1);Assert.AreEqual(plan.Last.ToDot(), tar.Year * 100 + 12);Assert.AreEqual(plan.First.Previous.ToDot(), tar.AddYears(-1).Year * 100 + 12);Assert.AreEqual(plan.Last.Next.ToDot(), tar.AddYears(1).Year * 100 + 1);Assert.AreEqual(plan.Quarter, GetQuarter(tar.Month));Assert.AreEqual(Monthly.MinValue, new Monthly(0, 1));Assert.AreEqual(Monthly.MaxValue, new Monthly(9999, 12));}private int GetQuarter(int q){if (new System.Collections.Generic.List<int>() { 1, 2, 3 }.Contains(q)) return 1;if (new System.Collections.Generic.List<int>() { 4, 5, 6 }.Contains(q)) return 2;if (new System.Collections.Generic.List<int>() { 7, 8, 9 }.Contains(q)) return 3;if (new System.Collections.Generic.List<int>() { 10, 11, 12 }.Contains(q)) return 4;return 0;}[TestMethod]public void TestMethods(){Monthly plan = 201801;var tar = new DateTime(2018, 1, 1);var tip = false;//DotAssert.AreEqual(new Monthly(0, 11), 11);Assert.AreEqual(new Monthly(1, 1), 101);Assert.AreEqual(new Monthly(100, 12), 10012);Assert.AreEqual(new Monthly(2018, 12), 201812);//TickesAssert.AreEqual(((Monthly)101).Tickes, 13);Assert.AreEqual(((Monthly)201811).Tickes, 2018 * 12 + 11);//加月Assert.AreEqual(plan.AddMonths(-1), 201712);Assert.AreEqual(plan.AddMonths(-23), 201602);Assert.AreEqual(plan.AddMonths(22), 201911);//加月(随机)for (int i = 0; i < 100; i++){var rd = new Random(Guid.NewGuid().GetHashCode()).Next(100);Assert.AreEqual(plan.AddMonths(rd), Monthly.FromDate(tar.AddMonths(rd)));Assert.AreEqual(plan.AddMonths(rd).Dot, tar.AddMonths(rd).Year * 100 + tar.AddMonths(rd).Month);}//加年Assert.IsTrue(plan.AddYears(6) == 202401);Assert.IsTrue(plan.AddYears(-18) == 200001);//加年（异常）try { var m = Monthly.Current.AddYears(-3000); }catch (Exception e) { if (e.Message.Contains("beteen 1 and 120000")) { tip = true; } }Assert.IsTrue(tip);//月份差Assert.AreEqual(plan.SpanMonths(201711), 2);Assert.AreEqual(plan.SpanMonths(201902), -13);//比较大小Assert.AreEqual(plan.CompareTo(201801), 0);Assert.AreEqual(plan.CompareTo(201701), 1);Assert.AreEqual(plan.CompareTo(202001), -1);//构造Assert.AreEqual(Monthly.FromDot(3), 3);Assert.AreEqual(Monthly.FromTickes(13), 101);Assert.AreEqual(Monthly.FromDate(new DateTime(2018, 12, 12)), 201812);Assert.AreEqual(Monthly.FromString("2018/01"), 201801);Assert.AreEqual(Monthly.FromString("2018年01月"), 201801);Assert.AreEqual(Monthly.FromString("2018@01/01"), 201801);Assert.AreEqual(Monthly.FromString((new DateTime(2018, 1, 1)).ToString()), 201801);Assert.AreEqual(Monthly.FromString("3"), 3);//月份轴var axis = Monthly.Axis(201711, 201901);Assert.IsTrue(axis.Count == 15);Assert.AreEqual(axis[0], 201711);Assert.AreEqual(axis[3], 201802);Assert.AreEqual(axis[14], 201901);axis = Monthly.Axis(201812, 201712);Assert.IsTrue(axis.Count == 13);Assert.AreEqual(axis[0], 201812);Assert.AreEqual(axis[12], 201712);//异常tip = false;try { Monthly m = 201800; }catch (Exception e) { if (e.Message.Contains("correct dot format")) { tip = true; } }  //dot formatAssert.IsTrue(tip);tip = false;try { Monthly m = Monthly.FromDot(13); }catch (Exception e) { if (e.Message.Contains("correct dot format")) { tip = true; } }  //13月Assert.IsTrue(tip);tip = false;try { Monthly m = Monthly.FromTickes(999999); }catch (Exception e) { if (e.Message.Contains("must beteen 1 and 120000")) { tip = true; } }  //越界Assert.IsTrue(tip);tip = false;try { Monthly m = Monthly.FromString(null); }catch (Exception e) { if (e.Message.Contains("null or empty")) { tip = true; } }  //IsNullOrEmptyAssert.IsTrue(tip);tip = false;try { Monthly m = Monthly.FromString("abc"); }catch (Exception e) { if (e.Message.Contains("parameters")) { tip = true; } }  //格式错误Assert.IsTrue(tip);tip = false;try { Monthly m = Monthly.FromString("88"); }catch (Exception e) { if (e.Message.Contains("must beteen")) { tip = true; } }  //越界Assert.IsTrue(tip);}[TestMethod]public void TestOps(){Monthly plan = 201801;var tar = Monthly.FromString("2018.01");Assert.AreEqual(plan + 12, 201901);Assert.AreEqual(plan - 13, 201612);Assert.AreEqual(plan - (Monthly)201701, 12);Assert.AreEqual(plan - (new DateTime(2017, 12, 12)), 1);Assert.AreEqual(--plan, 201712);Assert.AreEqual(++plan, 201801);Assert.IsTrue(plan == Monthly.FromDot(201801));Assert.IsTrue(plan != Monthly.FromDot(201802));Assert.IsTrue(plan >= Monthly.FromDot(201801));Assert.IsTrue(plan < Monthly.FromDot(201803));}[TestMethod]public void TestOvr(){Monthly plan = 201801;var tar = Monthly.FromString("2018.01");//哈希码(相同dot具有相同的哈希码)Assert.AreEqual(plan.GetHashCode(), tar.GetHashCode());tar++;Assert.AreNotEqual(plan.GetHashCode(), tar.GetHashCode());//格式化Assert.AreEqual(plan.ToString(), "2018/01");Assert.AreEqual(plan.ToString("yy/mm"), "18/01");Assert.AreEqual(Monthly.FromDot(501).ToString("yy/mm"), "05/01");Assert.AreEqual(plan.ToString("YYYY年m月"), "2018年1月");Assert.AreEqual(plan.ToString("公元YyYy年mM月,哈哈..."), "公元2018年01月,哈哈...");//比较相等Assert.IsTrue(plan.Equals(Monthly.FromDot(201801)));Assert.IsTrue(plan.Equals(new DateTime(2018, 1, 1)));Assert.IsTrue(plan.Equals((object)Monthly.FromDot(201801)));Assert.IsFalse(plan.Equals(Monthly.FromDot(201901)));}}
}

Monthly使用介绍

1.Monthly构造

  //创建一个“2018年1月”的账期Monthly m1 = 201801;Monthly m2 = new Monthly(2018, 1);Monthly m3 = Monthly.FromDate(new DateTime(2018, 1, 1));Monthly m4 = Monthly.FromDot(201801);Monthly m5 = Monthly.FromTickes(2018 * 12 + 1);Monthly m6 = Monthly.FromString("2018年01月");Monthly cur = Monthly.Current;   //当前时间实例Monthly min = Monthly.MinValue;  //Monthly最小实例Monthly max = Monthly.MaxValue;  //Monthly最大实例

2. Monthly属性

3.Monthly方法

• ToDot();
  说明：获取当前实例的年月标记值，如2018年1月记为 : 201801
  ​

• AddYears(int years)
  说明：以当前实例与years的和值为依据创建一个新实例

• AddMonths(int months)
  说明：以当前实例与months的和值为依据创建一个新实例
  ​
• Equals(Monthly other)
  说明：判断当前实例的值与给定实例的值是否相等
  ​
• Equals(object obj)
  说明：判断当前实例的值与给定实例的转换值是否相等，obj可以是DateTime类型
  ​
• SpanMonths(Monthly other)
  说明：获取当前实例与给定实例的月份差值
  ​
• SpanMonths(DateTime date)
  说明：获取当前实例与DateTime实例的月份差值
  ​
• CompareTo(Monthly other)
  说明：获取当前实例与给定实例的大小比较的结果标识， -1:小于other实例值 ； 0 等于other实例值 ； 1：大于other实例值
  ​
• List<Monthly> Axis(int from, int to)
  说明：获取一段时间内的Monthly数轴(包含开始与结束月份)
  ​
• List<Monthly> Axis(Monthly from, Monthly to)
  说明：同 List Axis(int from, int to)
  ​

• ToString(string format = "yyyy/mm")
  说明：获取包含"Y、y、M、m"字符格式的自定义Monthly字符串，format 格式如：yyyy/mm ; yy/mm ; yyyy年mm月 ;YYYY-Mm...，不区分大小写
  ​

示例：

   Monthly m = 201801;m.CompareTo(201701);            m.Equals(DateTime.Now);m.Equals(201701);m.SpanMonths(new DateTime(2017, 1, 1));m.SpanMonths(201701);m.ToString();m.ToString("yy/mm");Monthly.FromDot(501).ToString("yy/mm");m.ToString("YYYY年m月");m.ToString("公元YyYy年mM月,哈哈...");

4.Monthly操作符

Monthly支持+、- 、* 、/ 、> 、>= 、< 、<= 、++ 、-- 、== 、!= 运算符操作。

特别注意:-操作，他有operator -(Monthly m, int months)和operator -(Monthly m1, Monthly m2)两个重载版本，且方法功能不同，如果是第二个版本，则必须显式标注被减对象的数据类型，如m-(Monthly)201701

参考:
https://referencesource.microsoft.com/#mscorlib/system/datetime.cs,df6b1eba7461813b 微软Datetime数据类型