给定代表某人生日的DateTime，我如何计算他们的年龄（以年为单位）？
当前回答
这个经典问题值得野田时间来解决。
static int GetAge(LocalDate dateOfBirth)
{
Instant now = SystemClock.Instance.Now;
// The target time zone is important.
// It should align with the *current physical location* of the person
// you are talking about. When the whereabouts of that person are unknown,
// then you use the time zone of the person who is *asking* for the age.
// The time zone of birth is irrelevant!
DateTimeZone zone = DateTimeZoneProviders.Tzdb["America/New_York"];
LocalDate today = now.InZone(zone).Date;
Period period = Period.Between(dateOfBirth, today, PeriodUnits.Years);
return (int) period.Years;
}
用法：
LocalDate dateOfBirth = new LocalDate(1976, 8, 27);
int age = GetAge(dateOfBirth);
您可能还对以下改进感兴趣：
将时钟作为IClock传递，而不是使用SystemClock.Instance，将提高可测试性。目标时区可能会更改，因此您也需要DateTimeZone参数。
另请参阅我关于这个主题的博客文章：处理生日和其他周年纪念日
其他回答
我使用ScArcher2的解决方案来精确计算人的年龄，但我需要进一步计算他们的月和日以及年。
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;
}
我们是否需要考虑小于1岁的人？作为中国文化，我们将小婴儿的年龄描述为2个月或4周。
下面是我的实现，它不像我想象的那么简单，尤其是处理2/28这样的日期。
public static string HowOld(DateTime birthday, DateTime now)
{
if (now < birthday)
throw new ArgumentOutOfRangeException("birthday must be less than now.");
TimeSpan diff = now - birthday;
int diffDays = (int)diff.TotalDays;
if (diffDays > 7)//year, month and week
{
int age = now.Year - birthday.Year;
if (birthday > now.AddYears(-age))
age--;
if (age > 0)
{
return age + (age > 1 ? " years" : " year");
}
else
{// month and week
DateTime d = birthday;
int diffMonth = 1;
while (d.AddMonths(diffMonth) <= now)
{
diffMonth++;
}
age = diffMonth-1;
if (age == 1 && d.Day > now.Day)
age--;
if (age > 0)
{
return age + (age > 1 ? " months" : " month");
}
else
{
age = diffDays / 7;
return age + (age > 1 ? " weeks" : " week");
}
}
}
else if (diffDays > 0)
{
int age = diffDays;
return age + (age > 1 ? " days" : " day");
}
else
{
int age = diffDays;
return "just born";
}
}
此实现已通过以下测试用例。
[TestMethod]
public void TestAge()
{
string age = HowOld(new DateTime(2011, 1, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("1 year", age);
age = HowOld(new DateTime(2011, 11, 30), new DateTime(2012, 11, 30));
Assert.AreEqual("1 year", age);
age = HowOld(new DateTime(2001, 1, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("11 years", age);
age = HowOld(new DateTime(2012, 1, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("10 months", age);
age = HowOld(new DateTime(2011, 12, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("11 months", age);
age = HowOld(new DateTime(2012, 10, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("1 month", age);
age = HowOld(new DateTime(2008, 2, 28), new DateTime(2009, 2, 28));
Assert.AreEqual("1 year", age);
age = HowOld(new DateTime(2008, 3, 28), new DateTime(2009, 2, 28));
Assert.AreEqual("11 months", age);
age = HowOld(new DateTime(2008, 3, 28), new DateTime(2009, 3, 28));
Assert.AreEqual("1 year", age);
age = HowOld(new DateTime(2009, 1, 28), new DateTime(2009, 2, 28));
Assert.AreEqual("1 month", age);
age = HowOld(new DateTime(2009, 2, 1), new DateTime(2009, 3, 1));
Assert.AreEqual("1 month", age);
// NOTE.
// new DateTime(2008, 1, 31).AddMonths(1) == new DateTime(2009, 2, 28);
// new DateTime(2008, 1, 28).AddMonths(1) == new DateTime(2009, 2, 28);
age = HowOld(new DateTime(2009, 1, 31), new DateTime(2009, 2, 28));
Assert.AreEqual("4 weeks", age);
age = HowOld(new DateTime(2009, 2, 1), new DateTime(2009, 2, 28));
Assert.AreEqual("3 weeks", age);
age = HowOld(new DateTime(2009, 2, 1), new DateTime(2009, 3, 1));
Assert.AreEqual("1 month", age);
age = HowOld(new DateTime(2012, 11, 5), new DateTime(2012, 11, 30));
Assert.AreEqual("3 weeks", age);
age = HowOld(new DateTime(2012, 11, 1), new DateTime(2012, 11, 30));
Assert.AreEqual("4 weeks", age);
age = HowOld(new DateTime(2012, 11, 20), new DateTime(2012, 11, 30));
Assert.AreEqual("1 week", age);
age = HowOld(new DateTime(2012, 11, 25), new DateTime(2012, 11, 30));
Assert.AreEqual("5 days", age);
age = HowOld(new DateTime(2012, 11, 29), new DateTime(2012, 11, 30));
Assert.AreEqual("1 day", age);
age = HowOld(new DateTime(2012, 11, 30), new DateTime(2012, 11, 30));
Assert.AreEqual("just born", age);
age = HowOld(new DateTime(2000, 2, 29), new DateTime(2009, 2, 28));
Assert.AreEqual("8 years", age);
age = HowOld(new DateTime(2000, 2, 29), new DateTime(2009, 3, 1));
Assert.AreEqual("9 years", age);
Exception e = null;
try
{
age = HowOld(new DateTime(2012, 12, 1), new DateTime(2012, 11, 30));
}
catch (ArgumentOutOfRangeException ex)
{
e = ex;
}
Assert.IsTrue(e != null);
}
希望这有帮助。
我有一个定制的计算年龄的方法，加上一条奖金验证消息，以防有帮助：
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
}
方法调用此处并传递日期时间值（如果服务器设置为美国语言环境，则为MM/dd/yyyy）。将其替换为消息框或要显示的任何容器：
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
记住，您可以按任何方式格式化邮件。
我已经创建了一个SQL Server用户定义函数来计算某人的年龄，给定他们的出生日期。当您需要它作为查询的一部分时，这很有用：
using System;
using System.Data;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
public partial class UserDefinedFunctions
{
[SqlFunction(DataAccess = DataAccessKind.Read)]
public static SqlInt32 CalculateAge(string strBirthDate)
{
DateTime dtBirthDate = new DateTime();
dtBirthDate = Convert.ToDateTime(strBirthDate);
DateTime dtToday = DateTime.Now;
// get the difference in years
int years = dtToday.Year - dtBirthDate.Year;
// subtract another year if we're before the
// birth day in the current year
if (dtToday.Month < dtBirthDate.Month || (dtToday.Month == dtBirthDate.Month && dtToday.Day < dtBirthDate.Day))
years=years-1;
int intCustomerAge = years;
return intCustomerAge;
}
};
var startDate = new DateTime(2015, 04, 05);//your start date
var endDate = DateTime.Now;
var years = 0;
while(startDate < endDate)
{
startDate = startDate.AddYears(1);
if(startDate < endDate)
{
years++;
}
}
