Author: Jonas Bilinkevicius 

How to detect the regional settings of a system

Answer:

Here is some sample code to get the language's abbreviated name, e.g.: ENU.

1   { ... }
2   var
3     Buffer: PChar;
4     Size: integer;
5   begin
6     Size := GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_SABBREVLANGNAME, nil, 0);
7     GetMem(Buffer, Size);
8     try
9       GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_SABBREVLANGNAME, Buffer, Size);
10      Result := string(Buffer);
11    finally
12      FreeMem(Buffer);
13    end;
14  end;


This code gets the current Currency Symbol from Windows' regional settings:

15  function GetCurrencySymbol: string;
16  var
17    Res: Cardinal;
18  begin
19    Res := GetLocaleInfo(GetUserDefaultLCID, LOCALE_SCURRENCY, nil, 0);
20    SetLength(Result, Res);
21    Res := GetLocaleInfo(GetUserDefaultLCID, LOCALE_SMONDECIMALSEP, PChar(Result), 
22  Res);
23    if Res = 0 then
24      RaiseLastOSError;
25  end;