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

2需要解决的主要问题有:

1.计算准确年龄-以年、月、日等为单位。

2.计算人们普遍认为的年龄——人们通常不关心自己到底多大,他们只关心自己当年的生日是什么时候。


1的解决方案显而易见:

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

2的解决方案在确定总年龄时并不那么精确,但人们认为它是精确的。当人们“手动”计算年龄时,通常也会使用它:

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
}

注释2.:

这是我的首选解决方案我们不能使用DateTime.DayOfYear或TimeSpans,因为它们会在闰年中改变天数为了可读性,我只增加了几行

还有一个提示。。。我将为它创建两个静态重载方法,一个用于通用,另一个用于使用友好:

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

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

其他回答

这里有一个DateTime扩展程序,它将年龄计算添加到DateTime对象。

public static class AgeExtender
{
    public static int GetAge(this DateTime dt)
    {
        int d = int.Parse(dt.ToString("yyyyMMdd"));
        int t = int.Parse(DateTime.Today.ToString("yyyyMMdd"));
        return (t-d)/10000;
    }
}

要使用最近的年龄计算年龄:

var ts = DateTime.Now - new DateTime(1988, 3, 19);
var age = Math.Round(ts.Days / 365.0);

一句话的回答:

DateTime dateOfBirth = Convert.ToDateTime("01/16/1990");
var age = ((DateTime.Now - dateOfBirth).Days) / 365;

以下是使用DateTimeOffset和手动数学的答案:

var diff = DateTimeOffset.Now - dateOfBirth;
var sinceEpoch = DateTimeOffset.UnixEpoch + diff;

return sinceEpoch.Year - 1970;
var birthDate = ... // DOB
var resultDate = DateTime.Now - birthDate;

使用resultDate,您可以应用TimeSpan财产来显示任何内容。