问题
In my application, a user enters two dates. A scheduled start date, and a scheduled end date. We have to take those dates, and populate 4 fields, based on the difference.
So, lets say he selects 1st Jan, 2010 as a start, and 2nd of March, 2011 as the end, we need to end up with:
Years: 1 Months: 2 Weeks: 0 Days 1
Meaning the total duration is 1 year, 2 months and 1 day.
Is there a standard way of doing this? Or would I need to write a method that has a lot of pretty tricky logic to work it out? I was hoping I'd be lucky, and there would be a date-diff type .Net class available.
回答1:
I think TimeSpan is what you are looking for, but it does not do years or months because those vary in length.
The below example is from the above link;
// Define two dates.
DateTime date1 = new DateTime(2010, 1, 1, 8, 0, 15);
DateTime date2 = new DateTime(2010, 8, 18, 13, 30, 30);
// Calculate the interval between the two dates.
TimeSpan interval = date2 - date1;
Console.WriteLine("{0} - {1} = {2}", date2, date1, interval.ToString());
// Display individual properties of the resulting TimeSpan object.
Console.WriteLine(" {0,-35} {1,20}", "Value of Days Component:", interval.Days);
Console.WriteLine(" {0,-35} {1,20}", "Total Number of Days:", interval.TotalDays);
Console.WriteLine(" {0,-35} {1,20}", "Value of Hours Component:", interval.Hours);
Console.WriteLine(" {0,-35} {1,20}", "Total Number of Hours:", interval.TotalHours);
Console.WriteLine(" {0,-35} {1,20}", "Value of Minutes Component:", interval.Minutes);
Console.WriteLine(" {0,-35} {1,20}", "Total Number of Minutes:", interval.TotalMinutes);
Console.WriteLine(" {0,-35} {1,20:N0}", "Value of Seconds Component:", interval.Seconds);
Console.WriteLine(" {0,-35} {1,20:N0}", "Total Number of Seconds:", interval.TotalSeconds);
Console.WriteLine(" {0,-35} {1,20:N0}", "Value of Milliseconds Component:", interval.Milliseconds);
Console.WriteLine(" {0,-35} {1,20:N0}", "Total Number of Milliseconds:", interval.TotalMilliseconds);
Console.WriteLine(" {0,-35} {1,20:N0}", "Ticks:", interval.Ticks);
// the example displays the following output:
// 8/18/2010 1:30:30 PM - 1/1/2010 8:00:15 AM = 229.05:30:15
// Value of Days Component: 229
// Total Number of Days: 229.229340277778
// Value of Hours Component: 5
// Total Number of Hours: 5501.50416666667
// Value of Minutes Component: 30
// Total Number of Minutes: 330090.25
// Value of Seconds Component: 15
// Total Number of Seconds: 19,805,415
// Value of Milliseconds Component: 0
// Total Number of Milliseconds: 19,805,415,000
// Ticks: 198,054,150,000,000
回答2:
Heres a complete method, weeks are not included, but could be added relatively simply. It's a somewhat complex question (asked in a multitude of ways on stackoverflow and answered poorly in a multitude of ways), but none the less can be answered. The TimeSpan object gives us part of what we need, but only works up through days. I've written a significant number of tests against this method, if you find a hole, please post a comment.
What this will do is compare 2 dates, getting the years, months, days, hours, and minutes. (e.g. some event happened 1 year, 6 months, 3 days, 4 hours and 7 minutes ago)
Because this question has been asked and attempted to be answered so many times, I'm not sure this will ever even get noticed, but if so it should provide value.
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;
}
回答3:
You can use the DateDiff class of this free library:
// ----------------------------------------------------------------------
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
回答4:
I also needed this but, in my case, without the weeks part (so only years, months and days). Given that, here's what I made:
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));
If you want to show this more dynamically, you can also use this code:
//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);
回答5:
Investigate the C# TimeSpan structure. It doesn't do months or years, but it does do days. That makes things easier.
回答6:
public partial class Age1 : System.Web.UI.Page
{
private int Years;
private int Months;
private int Days;
DateTime Cday;
DateTime Bday;
protected void Page_Load(object sender, EventArgs e)
{
txtCurrentDate.Enabled = false;
txtCurrentDate.Text = DateTime.Now.ToString("g");
Cday = Convert.ToDateTime(txtCurrentDate.Text);
}
protected void Button1_Click(object sender, EventArgs e)
{
Bday = Convert.ToDateTime(txtBirthdate.Text);
AgeCaluclation(Bday, Cday);
txtBirthdate.Text = "";
txtCurrentDate.Text = "";
lblAge.Text = this.Years+" Years "+this.Months+" Months " +this.Days+ "Days";
}
private Age1 AgeCaluclation(DateTime Bday, DateTime Cday)
{
if ((Cday.Year - Bday.Year) > 0 ||
(((Cday.Year - Bday.Year) == 0) &&
((Bday.Month < Cday.Month) ||
((Bday.Month == Cday.Month) &&
(Bday.Day <= Cday.Day)))))
{
int DaysInBdayMonth = DateTime.DaysInMonth(Bday.Year, Bday.Month);
int DaysRemain = Cday.Day + (DaysInBdayMonth - Bday.Day);
if(Cday.Month > Bday.Month)
{
this.Years = Cday.Year - Bday.Year;
this.Months = Cday.Month - (Bday.Month + 1) + Math.Abs(DaysRemain / DaysInBdayMonth);
this.Days = (DaysRemain % DaysInBdayMonth + DaysInBdayMonth) % DaysInBdayMonth;
}
else if (Cday.Month == Bday.Month)
{
if (Cday.Day >= Bday.Day)
{
this.Years = Cday.Year - Bday.Year;
this.Months = 0;
this.Days = Cday.Day - Bday.Day;
}
else
{
this.Years = (Cday.Year - 1) - Bday.Year;
this.Months = 11;
this.Days = DateTime.DaysInMonth(Bday.Year, Bday.Month) - (Bday.Day - Cday.Day);
}
}
else
{
this.Years = (Cday.Year - 1) - Bday.Year;
this.Months = Cday.Month + (11 - Bday.Month) + Math.Abs(DaysRemain / DaysInBdayMonth);
this.Days = (DaysRemain % DaysInBdayMonth + DaysInBdayMonth) % DaysInBdayMonth;
}
}
else
{
throw new ArgumentException("Birthday date must be earlier than current date");
}
return this;
}
}
回答7:
I had created this one for returning difference in years,month and days between 2 dates.
public static Dictionary<string, int> TimeSpanToDateParts(DateTime fromDate,DateTime toDate)
{
int years;
int months;
int days;
Dictionary<string, int> dateParts = new Dictionary<string, int>();
if (toDate < fromDate)
{
return TimeSpanToDateParts(toDate,fromDate);
}
var span = toDate - fromDate;
months = 12 * (toDate.Year - fromDate.Year) + (toDate.Month - fromDate.Month);
if (toDate.CompareTo(fromDate.AddMonths(months).AddMilliseconds(-500)) <= 0)
{
--months;
}
years = months / 12;
months -= years * 12;
if (months == 0 && years == 0)
{
days = span.Days;
}
else
{
days = toDate.Day;
if (fromDate.Day > toDate.Day)
days = days + (DateTime.DaysInMonth(toDate.Year, toDate.Month - 1) - fromDate.Day);
else
days = days - fromDate.Day;
}
dateParts.Add("Years", years);
dateParts.Add("Months", months);
dateParts.Add("Days", days);
return dateParts;
}
来源：https://stackoverflow.com/questions/6260372/calculate-years-months-weeks-and-days