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);

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

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。

private int GetAge(int _year, int _month, int _day
{
    DateTime yourBirthDate= new DateTime(_year, _month, _day);

    DateTime todaysDateTime = DateTime.Today;
    int noOfYears = todaysDateTime.Year - yourBirthDate.Year;

    if (DateTime.Now.Month < yourBirthDate.Month ||
        (DateTime.Now.Month == yourBirthDate.Month && DateTime.Now.Day < yourBirthDate.Day))
    {
        noOfYears--;
    }

    return  noOfYears;
}

哇，我不得不在这里回答。。。这么简单的问题有很多答案。

private int CalcularIdade(DateTime dtNascimento)
    {
        var nHoje = Convert.ToInt32(DateTime.Today.ToString("yyyyMMdd"));
        var nAniversario = Convert.ToInt32(dtNascimento.ToString("yyyyMMdd"));

        double diff = (nHoje - nAniversario) / 10000;

        var ret = Convert.ToInt32(Math.Truncate(diff));

        return ret;
    }

这是一个非常适合我的功能。没有计算，非常简单。

    public static string ToAge(this DateTime dob, DateTime? toDate = null)
    {
        if (!toDate.HasValue)
            toDate = DateTime.Now;
        var now = toDate.Value;

        if (now.CompareTo(dob) < 0)
            return "Future date";

        int years = now.Year - dob.Year;
        int months = now.Month - dob.Month;
        int days = now.Day - dob.Day;

        if (days < 0)
        {
            months--;
            days = DateTime.DaysInMonth(dob.Year, dob.Month) - dob.Day + now.Day;
        }

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


        return string.Format("{0} year(s), {1} month(s), {2} days(s)",
            years,
            months,
            days);
    }

这里是一个单元测试：

    [Test]
    public void ToAgeTests()
    {
        var date = new DateTime(2000, 1, 1);
        Assert.AreEqual("0 year(s), 0 month(s), 1 days(s)", new DateTime(1999, 12, 31).ToAge(date));
        Assert.AreEqual("0 year(s), 0 month(s), 0 days(s)", new DateTime(2000, 1, 1).ToAge(date));
        Assert.AreEqual("1 year(s), 0 month(s), 0 days(s)", new DateTime(1999, 1, 1).ToAge(date));
        Assert.AreEqual("0 year(s), 11 month(s), 0 days(s)", new DateTime(1999, 2, 1).ToAge(date));
        Assert.AreEqual("0 year(s), 10 month(s), 25 days(s)", new DateTime(1999, 2, 4).ToAge(date));
        Assert.AreEqual("0 year(s), 10 month(s), 1 days(s)", new DateTime(1999, 2, 28).ToAge(date));

        date = new DateTime(2000, 2, 15);
        Assert.AreEqual("0 year(s), 0 month(s), 28 days(s)", new DateTime(2000, 1, 18).ToAge(date));
    }