1     public class TimeTool
 2     {
 3         //根據出生年月計算 整數天
 4         private static int GetAgeByBirthdate(DateTime birthdate)
 5         {
 6             DateTime now = DateTime.Now;
 7             int age = now.Year - birthdate.Year;
 8             if (now.Month < birthdate.Month || (now.Month == birthdate.Month && now.Day < birthdate.Day))
 9             {
10                 age--;
11             }
12             return age < 0 ? 0 : age;
13         }
           //根據出生年月計算 X歲或X月X天或X天
14         public static string GetAgeByBirthday(DateTime birthday)
15         {
16             var currenttime = DateTime.Now;
17             var diffTime = currenttime - birthday;
18             if (diffTime.TotalDays >= 365)
19             {
20                 //年齡計算
21                 return GetAgeByBirthdate(birthday).ToString() + "歲";
22             }
23             else
24             {
25                 //個月計算
26                 var diffmonth = currenttime.Month - birthday.Month;
27                 var day = currenttime.Day - birthday.Day;
28                 if (day < 0)
29                 {
30                     diffmonth--;
31                 }
32                 if (diffmonth > 0)
33                 {
34                     DateTime newbirthday = birthday.AddMonths(diffmonth);
35                     day = (int)((currenttime - newbirthday).TotalDays);
36                     return diffmonth.ToString() + "個月" + (day == 0 ? "" : day.ToString() + "天");
37                 }
38                 else
39                 {
40                     //直接計算天
41                     return ((int)(diffTime.TotalDays)).ToString() + "天";
42                 }
43             }
44 
45         }
46     }