Recognition of changed culture or time format

Question

I want to show the current day time in the current time format like:

DateTime now = DateTime.Now;  
textBlockTime.Text = now.ToString("T", culture);  

On app start the culture is set to CultureInfo.CurrentCulture.

When the user changed the culture or time format in Windows settings, I noticed that the Window receives the WM_WININICHANGE (WM_SETTINGCHANGE) message. So I could react and show the newly set time format, but how can I get to the new used culture or time format? In Windows setting it is also possible to change the time format without changing the culture.

Answer 1

You can use GetLocaleInfoEx in WM_SETTINGCHANGE to get the current formats

For example, a test for the Short Time :

            var sbDataUser = new StringBuilder(128);  
            if (GetLocaleInfoEx(LOCALE_NAME_USER_DEFAULT, LOCALE_SSHORTTIME, sbDataUser, sbDataUser.Capacity) != 0)  
            {  
                var sbDataSystem = new StringBuilder(128);  
                if (GetLocaleInfoEx(LOCALE_NAME_SYSTEM_DEFAULT, LOCALE_SSHORTTIME, sbDataSystem, sbDataSystem.Capacity) != 0)  
                {  
                    MessageBox.Show(string.Format("Time Format (User) : {0}\r\nTime Format (System) : {1}", sbDataUser.ToString(),  sbDataSystem.ToString()), "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);  
                }  
            }  

Declarations (cannot post here) : 107437

Answer 2

See the following

https://learn.microsoft.com/en-us/dotnet/standard/base-types/custom-date-and-time-format-strings

DateTimeFormatInfo.CurrentInfo.LongTimePattern = "TODO";  
DateTimeFormatInfo.CurrentInfo.ShortTimePattern = "TODO";  

Or

DateTimeFormatInfo formatInfo = new DateTimeFormatInfo()  
{  
    LongTimePattern = "TODO",  
    ShortTimePattern = "TODO"  
};