The Format function isn’t thread-safe unless you use the overload which takes a FormatSettings argument (because the FormatSettings-less version uses global variables). I use it to compose error messages in a thread I’m writing, and I want to use the same FormatSettings as the user would normally see in a GUI app. So here’s what I did. I added a TFormatSettings field to my thread class:
TMyThread = class(TThread)
private
FFormatSettings: TFormatSettings;
protected
procedure Execute; override;
end;Then I set it at the start of the Execute method:
procedure TMyThread.Execute;
begin
GetLocaleFormatSettings(LOCALE_SYSTEM_DEFAULT, FFormatSettings);
end; This seems to work well.
Update: On further thought I may be able to roll this all into the thread itself and not deal with it at creation time. But the important point is how to use GetThreadLocale and GetLocaleFormatSettings, which took some digging to find.
Update 2: I significantly changed how this works based on Yorai’s comments in Feedback.
{ 5 } Comments
From "Format Function" Delphi 7 Help file:
"The first form of Format is not thread-safe, because it uses localization information contained in global variables. The second form of Format, which is thread-safe, (…)"
"To populate FormatSettings with a set of default locale values, call GetLocaleFormatSettings."
Regards!
F.D.Castel
Yes, FD, I did read that, but there is no code example and it wasn’t obvious to me where to get the LCID argument.
Believe it or not I do use Help.
I’m having second thoughts about GetThreadLocale - lots of things can go wrong there (some are described at http://blogs.msdn.com/michkap/archive/2005/08/22/454360.aspx). To support the user’s settings, use LOCALE_USER_DEFAULT. If you want the system locale (since it seems you’re running this in a service), use LOCALE_SYSTEM_DEFAULT.
- Yorai
Thanks very much, Yorai! That’s excellent feedback. I’ll update the example with your suggestion. I wish this sort of thing were in the documentation.
Is there a QC about that issue?
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