格式的时间跨度有多年(Format A TimeSpan With Years)

我有2个日期属性的类： FirstDay和LastDay 。 LastDay可为空。 我想生成的格式的字符串"x year(s) y day(s)" 。 如果总年数都小于1，我想省略年份部分。 如果总天数都小于1，我想省略一天部分。 如果任一岁的日子是0，应该说“日/年”，而不是分别为“天/年”。

例子：
2.2年：“2年73天”
1.002738年：“1年3日”
0.2年：“73天”
2年备注： “2年”

我有工作，但它长：

private const decimal DaysInAYear = 365.242M;

public string LengthInYearsAndDays
{
    get
    {
        var lastDay = this.LastDay ?? DateTime.Today;
        var lengthValue = lastDay - this.FirstDay;

        var builder = new StringBuilder();

        var totalDays = (decimal)lengthValue.TotalDays;
        var totalYears = totalDays / DaysInAYear;
        var years = (int)Math.Floor(totalYears);

        totalDays -= (years * DaysInAYear);
        var days = (int)Math.Floor(totalDays);

        Func<int, string> sIfPlural = value =>
            value > 1 ? "s" : string.Empty;

        if (years > 0)
        {
            builder.AppendFormat(
                CultureInfo.InvariantCulture,
                "{0} year{1}",
                years,
                sIfPlural(years));

            if (days > 0)
            {
                builder.Append(" ");
            }
        }

        if (days > 0)
        {
            builder.AppendFormat(
                CultureInfo.InvariantCulture,
                "{0} day{1}",
                days,
                sIfPlural(days));
        }

        var length = builder.ToString();
        return length;
    }
}

是否有这样做（但仍可阅读）的更简洁的方式？

Answer 1:

一TimeSpan不具备的“年”一个明智的概念，因为它依赖于起点和终点。 （月相似 - 多少个月29天都没有好，这取决于...？）

为了给出一个无耻的插头，我的野田时间的项目使这很简单，但：

using System;
using NodaTime;

public class Test
{
    static void Main(string[] args)
    {
        LocalDate start = new LocalDate(2010, 6, 19);
        LocalDate end = new LocalDate(2013, 4, 11);
        Period period = Period.Between(start, end,
                                       PeriodUnits.Years | PeriodUnits.Days);

        Console.WriteLine("Between {0} and {1} are {2} years and {3} days",
                          start, end, period.Years, period.Days);
    }
}

输出：

Between 19 June 2010 and 11 April 2013 are 2 years and 296 days

Answer 2:

public string GetAgeText(DateTime birthDate)
{
        const double ApproxDaysPerMonth = 30.4375;
        const double ApproxDaysPerYear = 365.25;

        /*
        The above are the average days per month/year over a normal 4 year period
        We use these approximations as they are more accurate for the next century or so
        After that you may want to switch over to these 400 year approximations

           ApproxDaysPerMonth = 30.436875
           ApproxDaysPerYear  = 365.2425 

          How to get theese numbers:
            The are 365 days in a year, unless it is a leepyear.
            Leepyear is every forth year if Year % 4 = 0
            unless year % 100 == 1
            unless if year % 400 == 0 then it is a leep year.

            This gives us 97 leep years in 400 years. 
            So 400 * 365 + 97 = 146097 days.
            146097 / 400      = 365.2425
            146097 / 400 / 12 = 30,436875

        Due to the nature of the leap year calculation, on this side of the year 2100
        you can assume every 4th year is a leap year and use the other approximatiotions

        */
    //Calculate the span in days
    int iDays = (DateTime.Now - birthDate).Days;

    //Calculate years as an integer division
    int iYear = (int)(iDays / ApproxDaysPerYear);

    //Decrease remaing days
    iDays -= (int)(iYear * ApproxDaysPerYear);

    //Calculate months as an integer division
    int iMonths = (int)(iDays / ApproxDaysPerMonth);

    //Decrease remaing days
    iDays -= (int)(iMonths * ApproxDaysPerMonth);

    //Return the result as an string   
    return string.Format("{0} years, {1} months, {2} days", iYear, iMonths, iDays);
}

Answer 3:

我不会用做这个TimeSpan 。 日期数学只要你超越天，因为在一个月和天一年的天数不再是常数得到棘手。 这是可能的，为什么TimeSpan不包含性Years和Months 。 我反而确定的年/月/日两者之间的号码，等DateTime值，并相应地显示结果。

Answer 4:

我想，这应该工作：

public static int DiffYears(DateTime dateValue1, DateTime dateValue2)
{
    var intToCompare1 = Convert.ToInt32(dateValue1.ToString("yyyyMMdd"));
    var intToCompare2 = Convert.ToInt32(dateValue2.ToString("yyyyMMdd"));
    return (intToCompare2 - intToCompare1) / 10000;
}

Answer 5:

Public Function TimeYMDBetween(StartDate As DateTime, EndDate As DateTime) As String
    Dim Years As Integer = EndDate.Year - StartDate.Year
    Dim Months As Integer = EndDate.Month - StartDate.Month
    Dim Days As Integer = EndDate.Day - StartDate.Day
    Dim DaysLastMonth As Integer

    'figure out how many days were in last month
    If EndDate.Month = 1 Then
        DaysLastMonth = DateTime.DaysInMonth(EndDate.Year - 1, 12)
    Else
        DaysLastMonth = DateTime.DaysInMonth(EndDate.Year, EndDate.Month - 1)
    End If

    'adjust for negative days
    If Days < 0 Then
        Months = Months - 1
        Days = Days + DaysLastMonth 'borrowing from last month
    End If

    'adjust for negative Months
    If Months < 0 Then 'startdate hasn't happend this year yet
        Years = Years - 1
        Months = Months + 12
    End If

    Return Years.ToString() + " Years, " + Months.ToString() + " Months and " + Days.ToString() + " Days"

End Function

文章来源: Format A TimeSpan With Years