.net Culture specific 12/24 hour formatting

问题

Is there a way to keep the culture specific date time formatting but force 12/24 hour rendering? I know I can do a lot with the actual date/time format string like HH:mm:ss and hh:mm:ss but I would like to honor the current user culture formatting (i.e. mm/dd/yyyy or yyyy/mm/dd, etc), just force 12/24 hour time rendering.

回答1:

I'd probably do something like this:

        var culture = CultureInfo.CurrentCulture;
        var pattern = culture.DateTimeFormat.LongTimePattern; // or pick which one you want to use;
        var newPattern = pattern.Replace("h", "H").Replace("t", "");
        DateTime.Now.ToString(newPattern); // or use whatever DateTime you want to use

From the chat:

Here is a list of all cultures' long time pattern strings, and how they would be modified:

Old: hh:mm:ss tt New: HH:mm:ss 
Old: HH:mm:ss 'ч.' New: HH:mm:ss 'ч.'
Old: HH:mm:ss New: HH:mm:ss
Old: H:mm:ss New: H:mm:ss
Old: h:mm:ss tt New: H:mm:ss 
Old: tt h:mm:ss New:  H:mm:ss
Old: h:mm:ss.tt New: H:mm:ss.
Old: HH.mm.ss New: HH.mm.ss
Old: tt hh:mm:ss New:  HH:mm:ss

回答2:

You can use custom date/time format strings - e.g.:

For 12 hour rendering:

DateTime.Now.ToString("hh:mm:ss tt");

for 24-hour rendering:

DateTime.Now.ToString("HH:mm:ss");

To combine with a date format from the current culture, you can use one of:

DateTime.Now.ToString("d") + DateTime.Now.ToString(" hh:mm:ss tt");
DateTime.Now.ToString(CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern + 
                                      " hh:mm:ss tt");

回答3:

That depends on what cultures you're talking about. Some cultures don't accept 24 hour time, and others don't accept AM/PM. The safest choice is probably InvariantCulture.

回答4:

Use DateTime.ToShortTimeString() to ensure you get the version that is correct for your culture. Note: It does use the current culture settings of the thread by default.

Sample (from MSDN):

// This code example demonstrates the DateTime.ToLongDateString(),
// DateTime.ToLongTimeString(), DateTime.ToShortDateString(), and
// DateTime.ToShortTimeString() methods.

using System;
using System.Threading;
using System.Globalization;

class Sample 
{
    public static void Main() 
    {
    string msg1 = "The date and time patterns are defined in the DateTimeFormatInfo \n" +
                  "object associated with the current thread culture.\n";

// Initialize a DateTime object.
    Console.WriteLine("Initialize the DateTime object to May 16, 2001 3:02:15 AM.\n");
    DateTime myDateTime = new System.DateTime(2001, 5, 16, 3, 2, 15);

// Identify the source of the date and time patterns.
    Console.WriteLine(msg1);

// Display the name of the current culture.
    CultureInfo ci = Thread.CurrentThread.CurrentCulture;
    Console.WriteLine("Current culture: \"{0}\"\n", ci.Name);

// Display the long date pattern and string.
    Console.WriteLine("Long date pattern: \"{0}\"", ci.DateTimeFormat.LongDatePattern);
    Console.WriteLine("Long date string:  \"{0}\"\n", myDateTime.ToLongDateString());

// Display the long time pattern and string.
    Console.WriteLine("Long time pattern: \"{0}\"", ci.DateTimeFormat.LongTimePattern);
    Console.WriteLine("Long time string:  \"{0}\"\n", myDateTime.ToLongTimeString());

// Display the short date pattern and string.
    Console.WriteLine("Short date pattern: \"{0}\"", ci.DateTimeFormat.ShortDatePattern);
    Console.WriteLine("Short date string:  \"{0}\"\n", myDateTime.ToShortDateString());

// Display the short time pattern and string.
    Console.WriteLine("Short time pattern: \"{0}\"", ci.DateTimeFormat.ShortTimePattern);
    Console.WriteLine("Short time string:  \"{0}\"\n", myDateTime.ToShortTimeString());
    }
}

/*
This code example produces the following results:

Initialize the DateTime object to May 16, 2001 3:02:15 AM

The date and time patterns are defined in the DateTimeFormatInfo
object associated with the current thread culture.

Current culture: "en-US"

Long date pattern: "dddd, MMMM dd, yyyy"
Long date string:  "Wednesday, May 16, 2001"

Long time pattern: "h:mm:ss tt"
Long time string:  "3:02:15 AM"

Short date pattern: "M/d/yyyy"
Short date string:  "5/16/2001"

Short time pattern: "h:mm tt"
Short time string:  "3:02 AM"

*/

来源：https://stackoverflow.com/questions/8086890/net-culture-specific-12-24-hour-formatting

标签

wpf

datetime

cultureinfo