问从DateTime中以Years.Months格式计算年龄？

EN

using System;
using NodaTime;

class Test
{
    static void Main()
    {
        ShowAge(1988, 9, 6);
        ShowAge(1991, 3, 31);
        ShowAge(1991, 2, 25);
    }

    private static readonly PeriodType YearMonth =
        PeriodType.YearMonthDay.WithDaysRemoved();

    static void ShowAge(int year, int month, int day)
    {
        var birthday = new LocalDate(year, month, day);
        // For consistency for future readers :)
        var today = new LocalDate(2012, 2, 3);

        Period period = Period.Between(birthday, today, YearMonth);
        Console.WriteLine("Birthday: {0}; Age: {1} years, {2} months",
                          birthday, period.Years, period.Months);
    }
}

private static string AgeInYearsMonths(DateTime? DateOfBirth)
{
    if (DateOfBirth == null) return "";
    if (DateOfBirth >= DateTime.Today)
        throw new ArgumentException("DateOfBirth cannot be in future!");

    DateTime d = DateOfBirth.Value;
    int monthCount = 0;
    while ((d = d.AddMonths(1)) <= DateTime.Today)
    {
        monthCount++;
    }
    return string.Format("{0}.{1}", monthCount / 12, monthCount % 12);
}

var date=new DateTime(DateTime.Now.Subtract(new DateTime(1988,10,31)).Ticks);
Console.WriteLine((date.Year-1).ToString()+"."+(date.Month-1).ToString());