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

我的建议

int age = (int) ((DateTime.Now - bday).TotalDays/365.242199);

这一年似乎在正确的日期发生了变化。(我在107岁之前进行了现场测试。)

其他回答

我的建议

int age = (int) ((DateTime.Now - bday).TotalDays/365.242199);

这一年似乎在正确的日期发生了变化。(我在107岁之前进行了现场测试。)

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);

我认为TimeSpan包含了我们所需要的一切,而不必求助于365.25(或任何其他近似值)。扩展Aug的示例:

DateTime myBD = new DateTime(1980, 10, 10);
TimeSpan difference = DateTime.Now.Subtract(myBD);

textBox1.Text = difference.Years + " years " + difference.Months + " Months " + difference.Days + " days";

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;
    }
}

下面是一个测试片段:

DateTime bDay = new DateTime(2000, 2, 29);
DateTime now = new DateTime(2009, 2, 28);
MessageBox.Show(string.Format("Test {0} {1} {2}",
                CalculateAgeWrong1(bDay, now),      // outputs 9
                CalculateAgeWrong2(bDay, now),      // outputs 9
                CalculateAgeCorrect(bDay, now),     // outputs 8
                CalculateAgeCorrect2(bDay, now)));  // outputs 8

这里有一些方法:

public int CalculateAgeWrong1(DateTime birthDate, DateTime now)
{
    return new DateTime(now.Subtract(birthDate).Ticks).Year - 1;
}

public int CalculateAgeWrong2(DateTime birthDate, DateTime now)
{
    int age = now.Year - birthDate.Year;

    if (now < birthDate.AddYears(age))
        age--;

    return age;
}

public int CalculateAgeCorrect(DateTime birthDate, DateTime now)
{
    int age = now.Year - birthDate.Year;

    if (now.Month < birthDate.Month || (now.Month == birthDate.Month && now.Day < birthDate.Day))
        age--;

    return age;
}

public int CalculateAgeCorrect2(DateTime birthDate, DateTime now)
{
    int age = now.Year - birthDate.Year;

    // For leap years we need this
    if (birthDate > now.AddYears(-age)) 
        age--;
    // Don't use:
    // if (birthDate.AddYears(age) > now) 
    //     age--;

    return age;
}