可以这么简单：

int age = DateTime.Now.AddTicks(0 - dob.Ticks).Year - 1;

以下是计算某人年龄的最简单方法。计算某人的年龄非常简单，下面是计算方法！为了使代码正常工作，您需要一个名为BirthDate的DateTime对象，该对象包含生日。

 C#
        // get the difference in years
        int years = DateTime.Now.Year - BirthDate.Year; 
        // subtract another year if we're before the
        // birth day in the current year
        if (DateTime.Now.Month < BirthDate.Month || 
            (DateTime.Now.Month == BirthDate.Month && 
            DateTime.Now.Day < BirthDate.Day)) 
            years--;
  VB.NET
        ' get the difference in years
        Dim years As Integer = DateTime.Now.Year - BirthDate.Year
        ' subtract another year if we're before the
        ' birth day in the current year
        If DateTime.Now.Month < BirthDate.Month Or (DateTime.Now.Month = BirthDate.Month And DateTime.Now.Day < BirthDate.Day) Then 
            years = years - 1
        End If

因为闰年和所有事情，我知道的最好的方法是：

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

通过较少的转换和UtcNow，这段代码可以照顾闰年2月29日出生的人：

public int GetAge(DateTime DateOfBirth)
{
    var Now = DateTime.UtcNow;
    return Now.Year - DateOfBirth.Year -
        (
            (
                Now.Month > DateOfBirth.Month ||
                (Now.Month == DateOfBirth.Month && Now.Day >= DateOfBirth.Day)
            ) ? 0 : 1
        );
}

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;
    }

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;
    }
};