如何可视化各种 DateTime 格式的显示方式？答案

【问题标题】：How can I visualize the way various DateTime formats will display?如何可视化各种 DateTime 格式的显示方式？
【发布时间】：2012-07-18 02:17:28
【问题描述】：

我希望能够快速参考各种 DateTime 格式的显示方式，而不是费力地进行编辑、编译、gawk 和递归直到满意为止。

【问题讨论】：

标签： c# winforms datetime formatting datetime-format

【解决方案1】：

自定义日期时间格式

有以下自定义格式说明符 y（年）、M（月）、d（日）、h（12 小时）、H（24 小时）、m（分钟）、s（秒）、f（秒小数） )、F（第二个小数，尾随零被修剪）、t（PM 或 AM）和 z（时区）。

以下示例演示了如何将格式说明符重写为输出。 [C#]

    // create date time 2008-03-09 16:05:07.123
    DateTime dt = new DateTime(2008, 3, 9, 16, 5, 7, 123);
    String.Format("{0:y yy yyy yyyy}", dt);  // "8 08 008 2008"   year
    String.Format("{0:M MM MMM MMMM}", dt);  // "3 03 Mar March"  month
    String.Format("{0:d dd ddd dddd}", dt);  // "9 09 Sun Sunday" day
    String.Format("{0:h hh H HH}",     dt);  // "4 04 16 16"      hour 12/24
    String.Format("{0:m mm}",          dt);  // "5 05"            minute
    String.Format("{0:s ss}",          dt);  // "7 07"            second
    String.Format("{0:f ff fff ffff}", dt);  // "1 12 123 1230"   sec.fraction
    String.Format("{0:F FF FFF FFFF}", dt);  // "1 12 123 123"    without zeroes
    String.Format("{0:t tt}",          dt);  // "P PM"            A.M. or P.M.
    String.Format("{0:z zz zzz}",      dt);  // "-6 -06 -06:00"   time zone

您还可以使用日期分隔符 /（斜杠）和时间分隔符 :（冒号）。这些字符将被重写为当前 DateTimeFormatInfo.DateSeparator 和 DateTimeFormatInfo.TimeSeparator 中定义的字符。

    // date separator in german culture is "." (so "/" changes to ".")
    String.Format("{0:d/M/yyyy HH:mm:ss}", dt); // "9/3/2008 16:05:07" - english (en-US)
    String.Format("{0:d/M/yyyy HH:mm:ss}", dt); // "9.3.2008 16:05:07" - german (de-DE)

以下是一些自定义日期和时间格式的示例：

    // month/day numbers without/with leading zeroes
    String.Format("{0:M/d/yyyy}", dt);            // "3/9/2008"
    String.Format("{0:MM/dd/yyyy}", dt);          // "03/09/2008"

    // day/month names
    String.Format("{0:ddd, MMM d, yyyy}", dt);    // "Sun, Mar 9, 2008"
    String.Format("{0:dddd, MMMM d, yyyy}", dt);  // "Sunday, March 9, 2008"

    // two/four digit year
    String.Format("{0:MM/dd/yy}", dt);            // "03/09/08"
    String.Format("{0:MM/dd/yyyy}", dt);          // "03/09/2008"

标准日期时间格式

在 DateTimeFormatInfo 中定义了当前文化的标准模式。例如属性 ShortTimePattern 是字符串，其中包含值 h:mm tt 用于 en-US 文化和值 HH:mm 用于 de-DE 文化。

以下示例显示了 String.Format 方法中标准格式说明符的用法和结果输出。

    String.Format("{0:t}", dt);  //"4:05 PM"                           ShortTime
    String.Format("{0:d}", dt);  //"3/9/2008"                          ShortDate
    String.Format("{0:T}", dt);  //"4:05:07 PM"                        LongTime
    String.Format("{0:D}", dt);  //"Sunday, March 09, 2008"            LongDate
    String.Format("{0:f}", dt);  //"Sunday, March 09, 2008 4:05 PM"    LongDate+ShortTime
    String.Format("{0:F}", dt);  //"Sunday, March 09, 2008 4:05:07 PM" FullDateTime
    String.Format("{0:g}", dt);  //"3/9/2008 4:05 PM"                  ShortDate+ShortTime
    String.Format("{0:G}", dt);  //"3/9/2008 4:05:07 PM"               ShortDate+LongTime
    String.Format("{0:m}", dt);  //"March 09"                          MonthDay
    String.Format("{0:y}", dt);  //"March, 2008"                       YearMonth
    String.Format("{0:r}", dt);  //"Sun, 09 Mar 2008 16:05:07 GMT"     RFC1123
    String.Format("{0:s}", dt);  //"2008-03-09T16:05:07"               SortableDateTime
    String.Format("{0:u}", dt);  // "2008-03-09 16:05:07Z"             UniversalSortableDateTime

【讨论】：

【解决方案2】：

这显示了当前文化的所有格式：

StringBuilder sb = new StringBuilder();
foreach (string dateTimePattern in DateTimeFormatInfo.CurrentInfo.GetAllDateTimePatterns()) {
    sb.AppendFormat("{0} = {1}\r\n", dateTimePattern, DateTime.Now.ToString(dateTimePattern));
}

StringBuilder 之后的内容：

M/d/yyyy = 7/18/2012
M/d/yy = 7/18/12
MM/dd/yy = 07/18/12
MM/dd/yyyy = 07/18/2012
yy/MM/dd = 12/07/18
yyyy-MM-dd = 2012-07-18
dd-MMM-yy = 18-Jul-12
dddd, MMMM dd, yyyy = Wednesday, July 18, 2012
MMMM dd, yyyy = July 18, 2012
dddd, dd MMMM, yyyy = Wednesday, 18 July, 2012
dd MMMM, yyyy = 18 July, 2012
dddd, MMMM dd, yyyy h:mm tt = Wednesday, July 18, 2012 4:25 PM
dddd, MMMM dd, yyyy hh:mm tt = Wednesday, July 18, 2012 04:25 PM
dddd, MMMM dd, yyyy H:mm = Wednesday, July 18, 2012 16:25
dddd, MMMM dd, yyyy HH:mm = Wednesday, July 18, 2012 16:25
MMMM dd, yyyy h:mm tt = July 18, 2012 4:25 PM
MMMM dd, yyyy hh:mm tt = July 18, 2012 04:25 PM
MMMM dd, yyyy H:mm = July 18, 2012 16:25
MMMM dd, yyyy HH:mm = July 18, 2012 16:25
dddd, dd MMMM, yyyy h:mm tt = Wednesday, 18 July, 2012 4:25 PM
dddd, dd MMMM, yyyy hh:mm tt = Wednesday, 18 July, 2012 04:25 PM
dddd, dd MMMM, yyyy H:mm = Wednesday, 18 July, 2012 16:25
dddd, dd MMMM, yyyy HH:mm = Wednesday, 18 July, 2012 16:25
dd MMMM, yyyy h:mm tt = 18 July, 2012 4:25 PM
dd MMMM, yyyy hh:mm tt = 18 July, 2012 04:25 PM
dd MMMM, yyyy H:mm = 18 July, 2012 16:25
dd MMMM, yyyy HH:mm = 18 July, 2012 16:25
dddd, MMMM dd, yyyy h:mm:ss tt = Wednesday, July 18, 2012 4:25:17 PM
dddd, MMMM dd, yyyy hh:mm:ss tt = Wednesday, July 18, 2012 04:25:17 PM
dddd, MMMM dd, yyyy H:mm:ss = Wednesday, July 18, 2012 16:25:17
dddd, MMMM dd, yyyy HH:mm:ss = Wednesday, July 18, 2012 16:25:17
MMMM dd, yyyy h:mm:ss tt = July 18, 2012 4:25:17 PM
MMMM dd, yyyy hh:mm:ss tt = July 18, 2012 04:25:17 PM
MMMM dd, yyyy H:mm:ss = July 18, 2012 16:25:17
MMMM dd, yyyy HH:mm:ss = July 18, 2012 16:25:17
dddd, dd MMMM, yyyy h:mm:ss tt = Wednesday, 18 July, 2012 4:25:17 PM
dddd, dd MMMM, yyyy hh:mm:ss tt = Wednesday, 18 July, 2012 04:25:17 PM
dddd, dd MMMM, yyyy H:mm:ss = Wednesday, 18 July, 2012 16:25:17
dddd, dd MMMM, yyyy HH:mm:ss = Wednesday, 18 July, 2012 16:25:17
dd MMMM, yyyy h:mm:ss tt = 18 July, 2012 4:25:17 PM
dd MMMM, yyyy hh:mm:ss tt = 18 July, 2012 04:25:17 PM
dd MMMM, yyyy H:mm:ss = 18 July, 2012 16:25:17
dd MMMM, yyyy HH:mm:ss = 18 July, 2012 16:25:17
M/d/yyyy h:mm tt = 7/18/2012 4:25 PM
M/d/yyyy hh:mm tt = 7/18/2012 04:25 PM
M/d/yyyy H:mm = 7/18/2012 16:25
M/d/yyyy HH:mm = 7/18/2012 16:25
M/d/yy h:mm tt = 7/18/12 4:25 PM
M/d/yy hh:mm tt = 7/18/12 04:25 PM
M/d/yy H:mm = 7/18/12 16:25
M/d/yy HH:mm = 7/18/12 16:25
MM/dd/yy h:mm tt = 07/18/12 4:25 PM
MM/dd/yy hh:mm tt = 07/18/12 04:25 PM
MM/dd/yy H:mm = 07/18/12 16:25
MM/dd/yy HH:mm = 07/18/12 16:25
MM/dd/yyyy h:mm tt = 07/18/2012 4:25 PM
MM/dd/yyyy hh:mm tt = 07/18/2012 04:25 PM
MM/dd/yyyy H:mm = 07/18/2012 16:25
MM/dd/yyyy HH:mm = 07/18/2012 16:25
yy/MM/dd h:mm tt = 12/07/18 4:25 PM
yy/MM/dd hh:mm tt = 12/07/18 04:25 PM
yy/MM/dd H:mm = 12/07/18 16:25
yy/MM/dd HH:mm = 12/07/18 16:25
yyyy-MM-dd h:mm tt = 2012-07-18 4:25 PM
yyyy-MM-dd hh:mm tt = 2012-07-18 04:25 PM
yyyy-MM-dd H:mm = 2012-07-18 16:25
yyyy-MM-dd HH:mm = 2012-07-18 16:25
dd-MMM-yy h:mm tt = 18-Jul-12 4:25 PM
dd-MMM-yy hh:mm tt = 18-Jul-12 04:25 PM
dd-MMM-yy H:mm = 18-Jul-12 16:25
dd-MMM-yy HH:mm = 18-Jul-12 16:25
M/d/yyyy h:mm:ss tt = 7/18/2012 4:25:17 PM
M/d/yyyy hh:mm:ss tt = 7/18/2012 04:25:17 PM
M/d/yyyy H:mm:ss = 7/18/2012 16:25:17
M/d/yyyy HH:mm:ss = 7/18/2012 16:25:17
M/d/yy h:mm:ss tt = 7/18/12 4:25:17 PM
M/d/yy hh:mm:ss tt = 7/18/12 04:25:17 PM
M/d/yy H:mm:ss = 7/18/12 16:25:17
M/d/yy HH:mm:ss = 7/18/12 16:25:17
MM/dd/yy h:mm:ss tt = 07/18/12 4:25:17 PM
MM/dd/yy hh:mm:ss tt = 07/18/12 04:25:17 PM
MM/dd/yy H:mm:ss = 07/18/12 16:25:17
MM/dd/yy HH:mm:ss = 07/18/12 16:25:17
MM/dd/yyyy h:mm:ss tt = 07/18/2012 4:25:17 PM
MM/dd/yyyy hh:mm:ss tt = 07/18/2012 04:25:17 PM
MM/dd/yyyy H:mm:ss = 07/18/2012 16:25:17
MM/dd/yyyy HH:mm:ss = 07/18/2012 16:25:17
yy/MM/dd h:mm:ss tt = 12/07/18 4:25:17 PM
yy/MM/dd hh:mm:ss tt = 12/07/18 04:25:17 PM
yy/MM/dd H:mm:ss = 12/07/18 16:25:17
yy/MM/dd HH:mm:ss = 12/07/18 16:25:17
yyyy-MM-dd h:mm:ss tt = 2012-07-18 4:25:17 PM
yyyy-MM-dd hh:mm:ss tt = 2012-07-18 04:25:17 PM
yyyy-MM-dd H:mm:ss = 2012-07-18 16:25:17
yyyy-MM-dd HH:mm:ss = 2012-07-18 16:25:17
dd-MMM-yy h:mm:ss tt = 18-Jul-12 4:25:17 PM
dd-MMM-yy hh:mm:ss tt = 18-Jul-12 04:25:17 PM
dd-MMM-yy H:mm:ss = 18-Jul-12 16:25:17
dd-MMM-yy HH:mm:ss = 18-Jul-12 16:25:17
MMMM dd = July 18
MMMM dd = July 18
yyyy'-'MM'-'dd'T'HH':'mm':'ss.fffffffK = 2012-07-18T16:25:17.0961142-07:00
yyyy'-'MM'-'dd'T'HH':'mm':'ss.fffffffK = 2012-07-18T16:25:17.0961142-07:00
ddd, dd MMM yyyy HH':'mm':'ss 'GMT' = Wed, 18 Jul 2012 16:25:17 GMT
ddd, dd MMM yyyy HH':'mm':'ss 'GMT' = Wed, 18 Jul 2012 16:25:17 GMT
yyyy'-'MM'-'dd'T'HH':'mm':'ss = 2012-07-18T16:25:17
h:mm tt = 4:25 PM
hh:mm tt = 04:25 PM
H:mm = 16:25
HH:mm = 16:25
h:mm:ss tt = 4:25:17 PM
hh:mm:ss tt = 04:25:17 PM
H:mm:ss = 16:25:17
HH:mm:ss = 16:25:17
yyyy'-'MM'-'dd HH':'mm':'ss'Z' = 2012-07-18 16:25:17Z
dddd, MMMM dd, yyyy h:mm:ss tt = Wednesday, July 18, 2012 4:25:17 PM
dddd, MMMM dd, yyyy hh:mm:ss tt = Wednesday, July 18, 2012 04:25:17 PM
dddd, MMMM dd, yyyy H:mm:ss = Wednesday, July 18, 2012 16:25:17
dddd, MMMM dd, yyyy HH:mm:ss = Wednesday, July 18, 2012 16:25:17
MMMM dd, yyyy h:mm:ss tt = July 18, 2012 4:25:17 PM
MMMM dd, yyyy hh:mm:ss tt = July 18, 2012 04:25:17 PM
MMMM dd, yyyy H:mm:ss = July 18, 2012 16:25:17
MMMM dd, yyyy HH:mm:ss = July 18, 2012 16:25:17
dddd, dd MMMM, yyyy h:mm:ss tt = Wednesday, 18 July, 2012 4:25:17 PM
dddd, dd MMMM, yyyy hh:mm:ss tt = Wednesday, 18 July, 2012 04:25:17 PM
dddd, dd MMMM, yyyy H:mm:ss = Wednesday, 18 July, 2012 16:25:17
dddd, dd MMMM, yyyy HH:mm:ss = Wednesday, 18 July, 2012 16:25:17
dd MMMM, yyyy h:mm:ss tt = 18 July, 2012 4:25:17 PM
dd MMMM, yyyy hh:mm:ss tt = 18 July, 2012 04:25:17 PM
dd MMMM, yyyy H:mm:ss = 18 July, 2012 16:25:17
dd MMMM, yyyy HH:mm:ss = 18 July, 2012 16:25:17
MMMM, yyyy = July, 2012
MMMM, yyyy = July, 2012

我不知道为什么会重复几个模式。

【讨论】：

【解决方案3】：

我这样做过一次...我所做的是创建一个 Windows 应用程序，在其上放置一个标签和一个 TextBox，然后附加到 TextBox Change 事件 a

Label1.Text = DateTime.Now.ToString(TextBox1.Text)

非常简单，可以帮助您立即尝试。

【讨论】：

【解决方案4】：

DateTime.Now.ToString("D") displays "Wednesday, July 18, 2012"
DateTime.Now.ToString("d") displays "7/18/2012"
DateTime.Now.ToString("F") displays "Wednesday, July 18, 2012 3:57:13 PM"
DateTime.Now.ToString("f") displays "Wednesday, July 18, 2012 3:57 PM"
DateTime.Now.ToString("G") displays "7/18/2012 3:57 PM"
DateTime.Now.ToString("g") displays "7/18/2012 3:57:30 PM"
DateTime.Now.ToString("M") displays "July 18"
DateTime.Now.ToString("R") displays "Wed, 18 Jul 2012 15:57:55 GMT"
DateTime.Now.ToString("s") displays "2012-07-18T15:58:02"
DateTime.Now.ToString("T") displays "3:56:38 PM"
DateTime.Now.ToString("t") displays "3:56 PM"
DateTime.Now.ToString("U") displays "Wednesday, July 18, 2012 10:58:09 PM"
DateTime.Now.ToString("u") displays "2012-07-18 15:58:17Z"
DateTime.Now.ToString("Y") displays "July, 2012"
DateTime.Now.ToString("42") displays "42"

【讨论】：

.Today 或 .Now?我在您的结果中看到了时间。
你是对的；我更改了代码，但没有更改文本，我现在将这样做。谢谢。