cours année lrécupérer c# Comment puis-je calculer l'âge de quelqu'un en C #?



15 Answers

C'est une façon étrange de le faire, mais si vous formatez la date à yyyymmdd et soustrayez la date de naissance de la date actuelle, alors laissez tomber les 4 derniers chiffres que vous avez l'âge :)

Je ne connais pas C #, mais je crois que cela fonctionnera dans n'importe quelle langue.

20080814 - 19800703 = 280111 

Déposez les 4 derniers chiffres = 28 .

Code C #:

int now = int.Parse(DateTime.Now.ToString("yyyyMMdd"));
int dob = int.Parse(dateOfBirth.ToString("yyyyMMdd"));
int age = (now - dob) / 10000;

Ou alternativement sans toute la conversion de type sous la forme d'une méthode d'extension. Erreur lors de la vérification omise:

public static Int32 GetAge(this DateTime dateOfBirth)
{
    var today = DateTime.Today;

    var a = (today.Year * 100 + today.Month) * 100 + today.Day;
    var b = (dateOfBirth.Year * 100 + dateOfBirth.Month) * 100 + dateOfBirth.Day;

    return (a - b) / 10000;
}
comment calculer l année de naissance

Étant donné un DateTime représentant l'anniversaire d'une personne, comment puis-je calculer son âge en années?




Je ne pense pas que l'une des réponses à ce jour fournisse des cultures qui calculent l'âge différemment. Voir, par exemple, le calcul de l'âge de l'Asie de l'Est par rapport à celui de l'Ouest.

Toute vraie réponse doit inclure la localisation. Le modèle de stratégie serait probablement en ordre dans cet exemple.




Ma suggestion

int age = (int) ((DateTime.Now - bday).TotalDays/365.242199);

Cela semble changer l'année à la bonne date. (J'ai repéré testé jusqu'à l'âge de 107)




2 Les principaux problèmes à résoudre sont:

1. Calculer l'âge exact - en années, mois, jours, etc.

2. Calculer L'âge généralement perçu - les gens ne se soucient généralement pas de leur âge, ils se soucient seulement de leur anniversaire dans l'année en cours.

La solution pour 1 est évidente:

DateTime birth = DateTime.Parse("1.1.2000");
DateTime today = DateTime.Today;     //we usually don't care about birth time
TimeSpan age = today - birth;        //.NET FCL should guarantee this as precise
double ageInDays = age.TotalDays;    //total number of days ... also precise
double daysInYear = 365.2425;        //statistical value for 400 years
double ageInYears = ageInDays / daysInYear;  //can be shifted ... not so precise

La solution pour 2 est celle qui n'est pas si précise pour déterminer l'âge total, mais est perçue comme précise par les gens. Les gens l'utilisent aussi habituellement lorsqu'ils calculent leur âge «manuellement»:

DateTime birth = DateTime.Parse("1.1.2000");
DateTime today = DateTime.Today;
int age = today.Year - birth.Year;    //people perceive their age in years

if (today.Month < birth.Month ||
   ((today.Month == birth.Month) && (today.Day < birth.Day)))
{
  age--;  //birthday in current year not yet reached, we are 1 year younger ;)
          //+ no birthday for 29.2. guys ... sorry, just wrong date for birth
}

Notes à 2 .:

  • C'est ma solution préférée
  • Nous ne pouvons pas utiliser DateTime.DayOfYear ou TimeSpans, car ils décalent le nombre de jours dans les années bissextiles
  • Je l'ai mis un peu plus de lignes pour la lisibilité

Juste une note de plus ... Je voudrais créer deux méthodes statiques surchargées, une pour l'utilisation universelle, deuxièmement pour la convivialité:

public static int GetAge(DateTime bithDay, DateTime today) 
{ 
  //chosen solution method body
}

public static int GetAge(DateTime birthDay) 
{ 
  return GetAge(birthDay, DateTime.Now);
}



C'est la version que nous utilisons ici. Cela fonctionne, et c'est assez simple. C'est la même idée que celle de Jeff, mais je pense que c'est un peu plus clair parce que ça sépare la logique de la soustraction, donc c'est un peu plus facile à comprendre.

public static int GetAge(this DateTime dateOfBirth, DateTime dateAsAt)
{
    return dateAsAt.Year - dateOfBirth.Year - (dateOfBirth.DayOfYear < dateAsAt.DayOfYear ? 0 : 1);
}

Vous pourriez étendre l'opérateur ternaire pour le rendre encore plus clair, si vous pensez que ce genre de chose n'est pas clair.

Évidemment ceci est fait comme une méthode d'extension sur DateTime , mais clairement vous pouvez attraper cette ligne de code qui fait le travail et le mettre n'importe où. Ici, nous avons une autre surcharge de la méthode d'extension qui passe dans DateTime.Now , juste pour l'exhaustivité.




J'utilise ceci:

public static class DateTimeExtensions
{
    public static int Age(this DateTime birthDate)
    {
        return Age(birthDate, DateTime.Now);
    }

    public static int Age(this DateTime birthDate, DateTime offsetDate)
    {
        int result=0;
        result = offsetDate.Year - birthDate.Year;

        if (offsetDate.DayOfYear < birthDate.DayOfYear)
        {
              result--;
        }

        return result;
    }
}



La meilleure façon que je connaisse à cause des années bissextiles et tout est:

DateTime birthDate = new DateTime(2000,3,1);
int age = (int)Math.Floor((DateTime.Now - birthDate).TotalDays / 365.25D);

J'espère que cela t'aides.




J'ai passé du temps à travailler sur ce sujet et je suis arrivé avec ça pour calculer l'âge de quelqu'un en années, mois et jours. J'ai testé contre le problème du 29 février et les années bissextiles et cela semble fonctionner, j'apprécierais tout commentaire:

public void LoopAge(DateTime myDOB, DateTime FutureDate)
{
    int years = 0;
    int months = 0;
    int days = 0;

    DateTime tmpMyDOB = new DateTime(myDOB.Year, myDOB.Month, 1);

    DateTime tmpFutureDate = new DateTime(FutureDate.Year, FutureDate.Month, 1);

    while (tmpMyDOB.AddYears(years).AddMonths(months) < tmpFutureDate)
    {
        months++;

        if (months > 12)
        {
            years++;
            months = months - 12;
        }
    }

    if (FutureDate.Day >= myDOB.Day)
    {
        days = days + FutureDate.Day - myDOB.Day;
    }
    else
    {
        months--;

        if (months < 0)
        {
            years--;
            months = months + 12;
        }

        days +=
            DateTime.DaysInMonth(
                FutureDate.AddMonths(-1).Year, FutureDate.AddMonths(-1).Month
            ) + FutureDate.Day - myDOB.Day;

    }

    //add an extra day if the dob is a leap day
    if (DateTime.IsLeapYear(myDOB.Year) && myDOB.Month == 2 && myDOB.Day == 29)
    {
        //but only if the future date is less than 1st March
        if (FutureDate >= new DateTime(FutureDate.Year, 3, 1))
            days++;
    }

}



Garder cela simple (et peut-être stupide :)).

DateTime birth = new DateTime(1975, 09, 27, 01, 00, 00, 00);
TimeSpan ts = DateTime.Now - birth;
Console.WriteLine("You are approximately " + ts.TotalSeconds.ToString() + " seconds old.");



La façon la plus simple que j'ai jamais trouvée est celle-ci. Cela fonctionne correctement pour les environnements locaux américains et occidentaux. Impossible de parler à d'autres lieux, en particulier des endroits comme la Chine. 4 extra se compare, tout au plus, après le calcul initial de l'âge.

public int AgeInYears(DateTime birthDate, DateTime referenceDate)
{
  Debug.Assert(referenceDate >= birthDate, 
               "birth date must be on or prior to the reference date");

  DateTime birth = birthDate.Date;
  DateTime reference = referenceDate.Date;
  int years = (reference.Year - birth.Year);

  //
  // an offset of -1 is applied if the birth date has 
  // not yet occurred in the current year.
  //
  if (reference.Month > birth.Month);
  else if (reference.Month < birth.Month) 
    --years;
  else // in birth month
  {
    if (reference.Day < birth.Day)
      --years;
  }

  return years ;
}

I was looking over the answers to this and noticed that nobody has made reference to regulatory/legal implications of leap day births. For instance, per Wikipedia , if you're born on February 29th in various jurisdictions, you're non-leap year birthday varies:

  • In the United Kingdom and Hong Kong: it's the ordinal day of the year, so the next day, March 1st is your birthday.
  • In New Zealand: it's the previous day, February 28th for the purposes of driver licencing, and March 1st for other purposes.
  • Taiwan: it's February 28th.

And as near as I can tell, in the US, the statutes are silent on the matter, leaving it up to the common law and to how various regulatory bodies define things in their regulations.

To that end, an improvement:

public enum LeapDayRule
{
  OrdinalDay     = 1 ,
  LastDayOfMonth = 2 ,
}

static int ComputeAgeInYears(DateTime birth, DateTime reference, LeapYearBirthdayRule ruleInEffect)
{
  bool isLeapYearBirthday = CultureInfo.CurrentCulture.Calendar.IsLeapDay(birth.Year, birth.Month, birth.Day);
  DateTime cutoff;

  if (isLeapYearBirthday && !DateTime.IsLeapYear(reference.Year))
  {
    switch (ruleInEffect)
    {
      case LeapDayRule.OrdinalDay:
        cutoff = new DateTime(reference.Year, 1, 1)
                             .AddDays(birth.DayOfYear - 1);
        break;

      case LeapDayRule.LastDayOfMonth:
        cutoff = new DateTime(reference.Year, birth.Month, 1)
                             .AddMonths(1)
                             .AddDays(-1);
        break;

      default:
        throw new InvalidOperationException();
    }
  }
  else
  {
    cutoff = new DateTime(reference.Year, birth.Month, birth.Day);
  }

  int age = (reference.Year - birth.Year) + (reference >= cutoff ? 0 : -1);
  return age < 0 ? 0 : age;
}

It should be noted that this code assumes:

  • A western (European) reckoning of age, and
  • A calendar, like the Gregorian calendar that inserts a single leap day at the end of a month.



This is not a direct answer, but more of a philosophical reasoning about the problem at hand from a quasi-scientific point of view.

I would argue that the question does not specify the unit nor culture in which to measure age, most answers seem to assume an integer annual representation. The SI-unit for time is second , ergo the correct generic answer should be (of course assuming normalized DateTime and taking no regard whatsoever to relativistic effects):

var lifeInSeconds = (DateTime.Now.Ticks - then.Ticks)/TickFactor;

In the Christian way of calculating age in years:

var then = ... // Then, in this case the birthday
var now = DateTime.UtcNow;
int age = now.Year - then.Year;
if (now.AddYears(-age) < then) age--;

In finance there is a similar problem when calculating something often referred to as the Day Count Fraction , which roughly is a number of years for a given period. And the age issue is really a time measuring issue.

Example for the actual/actual (counting all days "correctly") convention:

DateTime start, end = .... // Whatever, assume start is before end

double startYearContribution = 1 - (double) start.DayOfYear / (double) (DateTime.IsLeapYear(start.Year) ? 366 : 365);
double endYearContribution = (double)end.DayOfYear / (double)(DateTime.IsLeapYear(end.Year) ? 366 : 365);
double middleContribution = (double) (end.Year - start.Year - 1);

double DCF = startYearContribution + endYearContribution + middleContribution;

Another quite common way to measure time generally is by "serializing" (the dude who named this date convention must seriously have been trippin'):

DateTime start, end = .... // Whatever, assume start is before end
int days = (end - start).Days;

I wonder how long we have to go before a relativistic age in seconds becomes more useful than the rough approximation of earth-around-sun-cycles during one's lifetime so far :) Or in other words, when a period must be given a location or a function representing motion for itself to be valid :)




Here's yet another answer:

public static int AgeInYears(DateTime birthday, DateTime today)
{
    return ((today.Year - birthday.Year) * 372 + (today.Month - birthday.Month) * 31 + (today.Day - birthday.Day)) / 372;
}

This has been extensively unit-tested. It does look a bit "magic". The number 372 is the number of days there would be in a year if every month had 31 days.

The explanation of why it works ( lifted from here ) is:

Let's set Yn = DateTime.Now.Year, Yb = birthday.Year, Mn = DateTime.Now.Month, Mb = birthday.Month, Dn = DateTime.Now.Day, Db = birthday.Day

age = Yn - Yb + (31*(Mn - Mb) + (Dn - Db)) / 372

We know that what we need is either Yn-Yb if the date has already been reached, Yn-Yb-1 if it has not.

a) If Mn<Mb , we have -341 <= 31*(Mn-Mb) <= -31 and -30 <= Dn-Db <= 30

-371 <= 31*(Mn - Mb) + (Dn - Db) <= -1

With integer division

(31*(Mn - Mb) + (Dn - Db)) / 372 = -1

b) If Mn=Mb and Dn<Db , we have 31*(Mn - Mb) = 0 and -30 <= Dn-Db <= -1

With integer division, again

(31*(Mn - Mb) + (Dn - Db)) / 372 = -1

c) If Mn>Mb , we have 31 <= 31*(Mn-Mb) <= 341 and -30 <= Dn-Db <= 30

1 <= 31*(Mn - Mb) + (Dn - Db) <= 371

With integer division

(31*(Mn - Mb) + (Dn - Db)) / 372 = 0

d) If Mn=Mb and Dn>Db , we have 31*(Mn - Mb) = 0 and 1 <= Dn-Db <= 3 0

With integer division, again

(31*(Mn - Mb) + (Dn - Db)) / 372 = 0

e) If Mn=Mb and Dn=Db , we have 31*(Mn - Mb) + Dn-Db = 0

and therefore (31*(Mn - Mb) + (Dn - Db)) / 372 = 0




I have a customized method to calculate age, plus a bonus validation message just in case it helps:

public void GetAge(DateTime dob, DateTime now, out int years, out int months, out int days)
{
    years = 0;
    months = 0;
    days = 0;

    DateTime tmpdob = new DateTime(dob.Year, dob.Month, 1);
    DateTime tmpnow = new DateTime(now.Year, now.Month, 1);

    while (tmpdob.AddYears(years).AddMonths(months) < tmpnow)
    {
        months++;
        if (months > 12)
        {
            years++;
            months = months - 12;
        }
    }

    if (now.Day >= dob.Day)
        days = days + now.Day - dob.Day;
    else
    {
        months--;
        if (months < 0)
        {
            years--;
            months = months + 12;
        }
        days += DateTime.DaysInMonth(now.AddMonths(-1).Year, now.AddMonths(-1).Month) + now.Day - dob.Day;
    }

    if (DateTime.IsLeapYear(dob.Year) && dob.Month == 2 && dob.Day == 29 && now >= new DateTime(now.Year, 3, 1))
        days++;

}   

private string ValidateDate(DateTime dob) //This method will validate the date
{
    int Years = 0; int Months = 0; int Days = 0;

    GetAge(dob, DateTime.Now, out Years, out Months, out Days);

    if (Years < 18)
        message =  Years + " is too young. Please try again on your 18th birthday.";
    else if (Years >= 65)
        message = Years + " is too old. Date of Birth must not be 65 or older.";
    else
        return null; //Denotes validation passed
}

Method call here and pass out datetime value (MM/dd/yyyy if server set to USA locale). Replace this with anything a messagebox or any container to display:

DateTime dob = DateTime.Parse("03/10/1982");  

string message = ValidateDate(dob);

lbldatemessage.Visible = !StringIsNullOrWhitespace(message);
lbldatemessage.Text = message ?? ""; //Ternary if message is null then default to empty string

Remember you can format the message any way you like.




I used ScArcher2's solution for an accurate Year calculation of a persons age but I needed to take it further and calculate their Months and Days along with the Years.

    public static Dictionary<string,int> CurrentAgeInYearsMonthsDays(DateTime? ndtBirthDate, DateTime? ndtReferralDate)
    {
        //----------------------------------------------------------------------
        // Can't determine age if we don't have a dates.
        //----------------------------------------------------------------------
        if (ndtBirthDate == null) return null;
        if (ndtReferralDate == null) return null;

        DateTime dtBirthDate = Convert.ToDateTime(ndtBirthDate);
        DateTime dtReferralDate = Convert.ToDateTime(ndtReferralDate);

        //----------------------------------------------------------------------
        // Create our Variables
        //----------------------------------------------------------------------
        Dictionary<string, int> dYMD = new Dictionary<string,int>();
        int iNowDate, iBirthDate, iYears, iMonths, iDays;
        string sDif = "";

        //----------------------------------------------------------------------
        // Store off current date/time and DOB into local variables
        //---------------------------------------------------------------------- 
        iNowDate = int.Parse(dtReferralDate.ToString("yyyyMMdd"));
        iBirthDate = int.Parse(dtBirthDate.ToString("yyyyMMdd"));

        //----------------------------------------------------------------------
        // Calculate Years
        //----------------------------------------------------------------------
        sDif = (iNowDate - iBirthDate).ToString();
        iYears = int.Parse(sDif.Substring(0, sDif.Length - 4));

        //----------------------------------------------------------------------
        // Store Years in Return Value
        //----------------------------------------------------------------------
        dYMD.Add("Years", iYears);

        //----------------------------------------------------------------------
        // Calculate Months
        //----------------------------------------------------------------------
        if (dtBirthDate.Month > dtReferralDate.Month)
            iMonths = 12 - dtBirthDate.Month + dtReferralDate.Month - 1;
        else
            iMonths = dtBirthDate.Month - dtReferralDate.Month;

        //----------------------------------------------------------------------
        // Store Months in Return Value
        //----------------------------------------------------------------------
        dYMD.Add("Months", iMonths);

        //----------------------------------------------------------------------
        // Calculate Remaining Days
        //----------------------------------------------------------------------
        if (dtBirthDate.Day > dtReferralDate.Day)
            //Logic: Figure out the days in month previous to the current month, or the admitted month.
            //       Subtract the birthday from the total days which will give us how many days the person has lived since their birthdate day the previous month.
            //       then take the referral date and simply add the number of days the person has lived this month.

            //If referral date is january, we need to go back to the following year's December to get the days in that month.
            if (dtReferralDate.Month == 1)
                iDays = DateTime.DaysInMonth(dtReferralDate.Year - 1, 12) - dtBirthDate.Day + dtReferralDate.Day;       
            else
                iDays = DateTime.DaysInMonth(dtReferralDate.Year, dtReferralDate.Month - 1) - dtBirthDate.Day + dtReferralDate.Day;       
        else
            iDays = dtReferralDate.Day - dtBirthDate.Day;             

        //----------------------------------------------------------------------
        // Store Days in Return Value
        //----------------------------------------------------------------------
        dYMD.Add("Days", iDays);

        return dYMD;
}



L'approche suivante (extrait de Time Period Library pour la classe .NET DateDiff ) considère le calendrier des informations de culture:

// ----------------------------------------------------------------------
private static int YearDiff( DateTime date1, DateTime date2 )
{
  return YearDiff( date1, date2, DateTimeFormatInfo.CurrentInfo.Calendar );
} // YearDiff

// ----------------------------------------------------------------------
private static int YearDiff( DateTime date1, DateTime date2, Calendar calendar )
{
  if ( date1.Equals( date2 ) )
  {
    return 0;
  }

  int year1 = calendar.GetYear( date1 );
  int month1 = calendar.GetMonth( date1 );
  int year2 = calendar.GetYear( date2 );
  int month2 = calendar.GetMonth( date2 );

  // find the the day to compare
  int compareDay = date2.Day;
  int compareDaysPerMonth = calendar.GetDaysInMonth( year1, month1 );
  if ( compareDay > compareDaysPerMonth )
  {
    compareDay = compareDaysPerMonth;
  }

  // build the compare date
  DateTime compareDate = new DateTime( year1, month2, compareDay,
    date2.Hour, date2.Minute, date2.Second, date2.Millisecond );
  if ( date2 > date1 )
  {
    if ( compareDate < date1 )
    {
      compareDate = compareDate.AddYears( 1 );
    }
  }
  else
  {
    if ( compareDate > date1 )
    {
      compareDate = compareDate.AddYears( -1 );
    }
  }
  return year2 - calendar.GetYear( compareDate );
} // YearDiff

Usage:

// ----------------------------------------------------------------------
public void CalculateAgeSamples()
{
  PrintAge( new DateTime( 2000, 02, 29 ), new DateTime( 2009, 02, 28 ) );
  // > Birthdate=29.02.2000, Age at 28.02.2009 is 8 years
  PrintAge( new DateTime( 2000, 02, 29 ), new DateTime( 2012, 02, 28 ) );
  // > Birthdate=29.02.2000, Age at 28.02.2012 is 11 years
} // CalculateAgeSamples

// ----------------------------------------------------------------------
public void PrintAge( DateTime birthDate, DateTime moment )
{
  Console.WriteLine( "Birthdate={0:d}, Age at {1:d} is {2} years", birthDate, moment, YearDiff( birthDate, moment ) );
} // PrintAge





Related