Hi,

same lazarus app, compiled on Windows XP, german localization:

Code:
MessageDlg('Title', 'Text', mtInformation, [ mbCancel, mbYes, mbNo], 0);

You get buttons Captions 'Yes' and 'No' until you add:

procedure TForm1.FormCreate(Sender: TObject);
    var
      PODirectory, Lang, FallbackLang: String;
   begin
       PODirectory := 'C:\lazarus\lcl\languages\';
      //PODirectory := '/home/john1/lazarus/lcl/languages/';
      GetLanguageIDs(Lang, FallbackLang); // in unit gettext
      TranslateUnitResourceStrings('LCLStrConsts', PODirectory + 'lclstrconsts.%s.po', Lang, FallbackLang);
      MessageDlg('Title', 'Text', mtInformation, [ mbCancel, mbYes, mbNo], 0);
    end;

The same app compiled on my Debain Sid, i get
buttons Captions 'Ja' and 'Nein' even if i comment out the code above.

Isn't there a easier way to handle this problem for Win XP? I got the above solution from lazarus wiki and i thought, how to solve this the Delphi way?

I think it's WM magic, replacing buttoncaptions Yes, No etc to locale.

Isn't there a easier way to handle this problem for Win XP? I got the above solution from lazarus wiki and i thought, how to solve this the Delphi way?

And what would be the Delphi way?

If (like me) you are only interested in translating into one language (German I guess) it maybe easier to include the po-file as a Lazarus resource in a unit and do the translation from there. If you do this in the initialization section of this unit, then you only have to include the unit in the uses clause to get German translations of the LCL resourcestrings.
You might periodically have to refesh the resouce if the po-file changes)

I have a code example for this (the code example on the wiki doesn't work for me).

Bart

The same app compiled on my Debain Sid, i get buttons Captions 'Ja' and 'Nein' even if i comment out the code above.

AFAIK your system locale is the default, either you have to provide language choice options or hardcode the language you want to translator functions.