使用DateTime.ToString时，Windows 10中的时间输出（AM / PM）发生了变化（＆＃34; tt＆＃34;）

Question

我最近升级到了Windows 10 - 我现在看到使用＆＃34; tt＆＃34;时的日期输出发生了一些意想不到的变化。格式说明符。

以下是一些演示此问题的代码：

using System.IO;
using System;
using System.Globalization;
using System.Threading.Tasks;

class Program
{
    static void Main()
    {
        var cultures = new string[] {null, "en-NZ", "en-US", "en-AU", "en-GB"};

            foreach (var culture in cultures) {
                if (culture != null) {
                    var c = CultureInfo.GetCultureInfo(culture);
                    System.Threading.Thread.CurrentThread.CurrentCulture = System.Threading.Thread.CurrentThread.CurrentUICulture = c;
                }

                DateTime dt = new DateTime(2015, 1, 2, 3, 4, 5, DateTimeKind.Utc);

                Console.WriteLine("selection: {0} CurrentThread.CurrentCulture.Name: {1} CurrentThread.CurrentUICulture.Name: {2}  Value: {3}",
                    culture ?? "ambient",
                    System.Threading.Thread.CurrentThread.CurrentCulture.Name,
                    System.Threading.Thread.CurrentThread.CurrentUICulture.Name,
                    dt.ToString("hhh:mm tt"));
            }
    }
}

以前版本的Windows中的输出是：

selection: ambient CurrentThread.CurrentCulture.Name: en-NZ CurrentThread.CurrentUICulture.Name: en-NZ Value: 03:04 a.m.
selection: en-NZ CurrentThread.CurrentCulture.Name: en-NZ CurrentThread.CurrentUICulture.Name: en-NZ Value: 03:04 a.m.
selection: en-US CurrentThread.CurrentCulture.Name: en-US CurrentThread.CurrentUICulture.Name: en-US Value: 03:04 AM
selection: en-AU CurrentThread.CurrentCulture.Name: en-AU CurrentThread.CurrentUICulture.Name: en-AU Value: 03:04 AM
selection: en-GB CurrentThread.CurrentCulture.Name: en-GB CurrentThread.CurrentUICulture.Name: en-GB Value: 03:04 am

在Windows 10中：

selection: ambient (windows 10) CurrentThread.CurrentCulture.Name: en-NZ CurrentThread.CurrentUICulture.Name: en-US  Value: 03:04 a.m.
selection: en-NZ CurrentThread.CurrentCulture.Name: en-NZ CurrentThread.CurrentUICulture.Name: en-NZ  Value: 03:04 AM
selection: en-US CurrentThread.CurrentCulture.Name: en-US CurrentThread.CurrentUICulture.Name: en-US  Value: 03:04 AM
selection: en-AU CurrentThread.CurrentCulture.Name: en-AU CurrentThread.CurrentUICulture.Name: en-AU  Value: 03:04 AM
selection: en-GB CurrentThread.CurrentCulture.Name: en-GB CurrentThread.CurrentUICulture.Name: en-GB  Value: 03:04 AM

在这两种情况下，此代码都是编译获胜的Visual Studio 2013，目标是.Net Framework 4.5

有没有人知道为什么行为发生了变化 - 为什么在Windows 10中看起来在线程上设置任何文化都会特别改变AM / PM的输出格式为＆＃34; AM＆＃34; /＆＃34; PM＆＃34;不是通常输出的文化？

Answer 1

你可能想看看＆＃34;文化数据不应该被认为是稳定的＆＃34; http://blogs.msdn.com/b/shawnste/archive/2005/04/05/405694.aspx

有一点是我们开始利用CLDR（通用语言环境数据存储库，http://cldr.unicode.org）来处理许多语言环境，以更好地符合行业标准。您可能已经注意到，我们现在有很多其他语言环境可供您使用。

Answer 2

在将DateTime更改为使用ToString("G")函数的字符串时，我总是强制使用ToString()。然后我没有问题再次将字符串解析为DateTime。我在Windows 7/8/10上使用我的客户端应用程序（以“G”格式获取日期和时间，并将其解析为DateTime）进行测试。

Answer 3

I also found that the combination of 'en-nz' and Windows 10 upgrade suddenly change a.m./p.m.to AM/PM.

The difference is the code I maintained relaying on ToShortTimeString() output with a.m./p.m. but in Windows 10 it changes to AM/PM instead I spend ages trying to find the correct culture info/format string, and I am also trying to find the missing local setting on my new Windows 10 machine compare to my old Windows 7 machine. But it turns out that the same local setting on different version of Windows machine does indeed display a.m./p.m. AM/PM differently.

同时确认{en-nz'的DateTimeFormatInfo.AMDesignator现在输出'AM'而不是'a.m。'