计算年,月,周和日

Question

在我的应用程序中,用户输入两个日期.计划的开始日期和计划的结束日期.我们必须采用这些日期,并根据差异填充4个字段.

所以,让我们说他选择2010年1月1日作为开始,2011年3月2日作为结束,我们需要最终:

年:1个月:2周:0天1

意思是总持续时间为1年,2个月和1天.

有这样做的标准方法吗？或者我是否需要编写一个具有很多非常棘手的逻辑的方法来解决它？我希望我很幸运,并且会有一个date-diff类型.Net类可用.

Answer 1

这是一个完整的方法,不包括数周,但可以相对简单地添加.这是一个比较复杂的问题(在对计算器多种方式询问和管理不善回答多种方式),但没有少都可以回答.TimeSpan对象为我们提供了我们需要的部分内容,但只能使用几天.我已经针对这种方法编写了大量测试,如果你发现了漏洞,请发表评论.

这将做的是比较2个日期,得到年,月,日,小时和分钟.(例如某些事件发生在1年,6个月,3天,4小时和7分钟前)

因为这个问题已被提出并试图回答这么多次,我不确定这会不会被注意到,但如果是这样的话它应该提供价值.

    public static void TimeSpanToDateParts(DateTime d1, DateTime d2, out int years, out int months, out int days, out int hours, out int minutes)
    {
        if (d1 < d2)
        {
            var d3 = d2;
            d2 = d1;
            d1 = d3;
        }

        var span = d1 - d2;

        months = 12 * (d1.Year - d2.Year) + (d1.Month - d2.Month);

        //month may need to be decremented because the above calculates the ceiling of the months, not the floor.
        //to do so we increase d2 by the same number of months and compare.
        //(500ms fudge factor because datetimes are not precise enough to compare exactly)
        if (d1.CompareTo(d2.AddMonths(months).AddMilliseconds(-500)) <= 0)
        {
            --months;
        }

        years = months / 12;
        months -= years * 12;

        if (months == 0 && years == 0)
        {
            days = span.Days;
        }
        else
        {
            var md1 = new DateTime(d1.Year, d1.Month, d1.Day);
            // Fixed to use d2.Day instead of d1.Day
            var md2 = new DateTime(d2.Year, d2.Month, d2.Day);
            var mDays = (int) (md1 - md2).TotalDays;

            if (mDays > span.Days)
            {
                mDays = (int)(md1.AddMonths(-1) - md2).TotalDays;
            }

            days = span.Days - mDays;


        }
        hours = span.Hours;
        minutes = span.Minutes;
    }

Answer 2

您可以使用此免费库的DateDiff类：

// ----------------------------------------------------------------------
public void DateDiffSample()
{
  DateTime date1 = new DateTime( 2009, 11, 8, 7, 13, 59 );
  Console.WriteLine( "Date1: {0}", date1 );
  // > Date1: 08.11.2009 07:13:59
  DateTime date2 = new DateTime( 2011, 3, 20, 19, 55, 28 );
  Console.WriteLine( "Date2: {0}", date2 );
  // > Date2: 20.03.2011 19:55:28

  DateDiff dateDiff = new DateDiff( date1, date2 );

  // differences
  Console.WriteLine( "DateDiff.Years: {0}", dateDiff.Years );
  // > DateDiff.Years: 1
  Console.WriteLine( "DateDiff.Quarters: {0}", dateDiff.Quarters );
  // > DateDiff.Quarters: 5
  Console.WriteLine( "DateDiff.Months: {0}", dateDiff.Months );
  // > DateDiff.Months: 16
  Console.WriteLine( "DateDiff.Weeks: {0}", dateDiff.Weeks );
  // > DateDiff.Weeks: 70
  Console.WriteLine( "DateDiff.Days: {0}", dateDiff.Days );
  // > DateDiff.Days: 497
  Console.WriteLine( "DateDiff.Weekdays: {0}", dateDiff.Weekdays );
  // > DateDiff.Weekdays: 71
  Console.WriteLine( "DateDiff.Hours: {0}", dateDiff.Hours );
  // > DateDiff.Hours: 11940
  Console.WriteLine( "DateDiff.Minutes: {0}", dateDiff.Minutes );
  // > DateDiff.Minutes: 716441
  Console.WriteLine( "DateDiff.Seconds: {0}", dateDiff.Seconds );
  // > DateDiff.Seconds: 42986489

  // elapsed
  Console.WriteLine( "DateDiff.ElapsedYears: {0}", dateDiff.ElapsedYears );
  // > DateDiff.ElapsedYears: 1
  Console.WriteLine( "DateDiff.ElapsedMonths: {0}", dateDiff.ElapsedMonths );
  // > DateDiff.ElapsedMonths: 4
  Console.WriteLine( "DateDiff.ElapsedDays: {0}", dateDiff.ElapsedDays );
  // > DateDiff.ElapsedDays: 12
  Console.WriteLine( "DateDiff.ElapsedHours: {0}", dateDiff.ElapsedHours );
  // > DateDiff.ElapsedHours: 12
  Console.WriteLine( "DateDiff.ElapsedMinutes: {0}", dateDiff.ElapsedMinutes );
  // > DateDiff.ElapsedMinutes: 41
  Console.WriteLine( "DateDiff.ElapsedSeconds: {0}", dateDiff.ElapsedSeconds );
  // > DateDiff.ElapsedSeconds: 29
} // DateDiffSample

Answer 3

我也需要这个，但就我而言，没有周部分（所以只有年、月和日）。鉴于此，这就是我所做的：

DateTime startDate = DateTime.ParseExact (start, "dd/MM/yyyy",CultureInfo.InvariantCulture);
DateTime endDate = DateTime.ParseExact (end, "dd/MM/yyyy",CultureInfo.InvariantCulture);
int days=0;
int months = 0;
int years = 0;
//calculate days
if (endDate.Day >= startDate.Day) {
    days = endDate.Day - startDate.Day;
} else {
    var tempDate = endDate.AddMonths (-1);
    int daysInMonth = DateTime.DaysInMonth (tempDate.Year, tempDate.Month);
    days = daysInMonth - (startDate.Day - endDate.Day);
    months--;
}
//calculate months
if (endDate.Month >= startDate.Month) {
    months+=endDate.Month - startDate.Month;
} else {
    months+= 12 - (startDate.Month - endDate.Month);
    years--;
}
//calculate years
years+=endDate.Year - startDate.Year;
Debug.WriteLine (string.Format("{0} years, {1} months, {2} days",years,months,days));

如果你想更动态地显示这一点，你也可以使用以下代码：

//build the string
var result = "";
if (years!=0){
    result = years == 1 ? years + " year" : years + " years";
}
if (months != 0) {
    if (result != "") {
        result += ", ";
    }
    result += months == 1 ? months + " month" : months + " months";
}
if (days != 0) {
    if (result != "") {
        result += ", ";
    }
    result += days == 1 ? days + " day" : days + " days";
}
Debug.WriteLine (result);