.NET中DateTime.Now.ToString显示毫秒：
DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff")
DateTime.Now.ToString的其他格式化字符串：
| 格式化字符串 |
释义 |
示例 |
| D |
long date |
Thursday, 10 April 2008 |
| d |
short date |
04/10/2008 |
| F |
full date long |
Thursday, 10 April 2008 06:30:00 |
| f |
full date short |
Thursday, 10 April 2008 06:30 |
| G |
general long |
04/10/2008 06:30:00 |
| g |
general short |
04/10/2008 06:30 |
| M |
month |
April 10 |
| O |
ISO 8601 |
2008-04-10T06:30:00.0000000 |
| R |
RFC 1123 |
Thu, 10 Apr 2008 06:30:00 GMT |
| s |
sortable |
2008-04-10T06:30:00 |
| T |
long time |
06:30:00 |
| t |
short time |
06:30 |
| U |
universal full |
Wednesday, 09 April 2008 22:30:00 |
| u |
universal sortable |
2008-04-10 06:30:00Z |
| Y |
year month |
2008 April |
| yy-MM-dd |
custom |
08-04-10 |
| yyyy MMMM dd |
custom |
2008 April 08 |
| yy-MMMM-dd ddd |
custom |
08-Apr-8 Tue |
| yyyy-M-d dddd |
custom |
2008-4-8 Tuesday |
| hh:mm:ss t z |
custom |
04:03:05 P -7 |
| h:mm:ss tt zz |
custom |
4:03:05 PM -07 |
| HH:mm:ss tt zz |
custom |
16:03:05 PM -07 |
| HH:m:s tt zzz |
custom |
16:3:5 PM -07:00 |
以上来源ReSharper。
当然也可以使用DateTime类提供的属性（如：DateTime.Now.Year）和方法（如：DateTime.Now.ToShortDateString()）。
以上内容比较简单，但遇到某些需求还挺好用的~