function RegKeyGetStrEx( Key: HKey; const ValueName: KOLString ): KOLString;
Like RegKeyGetStr, but accepts REG_EXPAND_SZ type, expanding all
  environment variables in resulting string.

program Test;

uses
 Windows, Messages, KOL;

var
 RegKey: HKEY;
 StrList: PStrList;

begin
 StrList := NewStrList;
 RegKey := RegKeyOpenCreate(HKEY_CURRENT_USER,'Software\KOL Test');
 try
   RegKeySetStr(RegKey,'Test_String1','Test_Value1');
   RegKeySetStr(RegKey,'Test_String2','Test_Value2'); // Only crashes if more than one item
   RegKeyGetValueNames(RegKey,StrList); // Crash here if UNICODE_CTRLS is defined
 finally
   RegKeyClose(RegKey);
   StrList.Free;
 end;
end.

//[function RegKeyGetValueNames]
{$IFDEF OLD_REGKEYGETVALUENAMES}
function RegKeyGetValueNames(const Key: HKEY; List: PKOLStrList): Boolean;
var
 I, Size, NumSubKeys, NumValueNames, MaxValueNameLen: DWORD;
 ValueName: KOLString;
begin
 List.Clear ;
 Result:=False;
 if RegQueryInfoKey(Key, nil, nil, nil, @NumSubKeys, nil, nil, @NumValueNames,
@MaxValueNameLen, nil, nil, nil) = ERROR_SUCCESS then
 begin
    if NumValueNames > 0 then
       for I := 0 to NumValueNames - 1 do begin
         Size := MaxValueNameLen + 1;
         SetLength(ValueName, Size);
         FillChar(ValueName[1],Size,#0);
         RegEnumValue(Key, I, @ValueName[1], Size, nil, nil, nil, nil);
         ValueName := Trim(ValueName);
         List.Add(ValueName);
       end;
    Result := True;
 end ;
end;
{$ELSE} // new (faster) version by Alex Shyshko (Psychedelic)
function RegKeyGetValueNames(const Key: HKEY; List: PKOLStrList) : Boolean;
var
 i, MaxValueNameLen, Size: DWORD;
 Buf: PKOLchar;
begin
Result:=false;
List.Clear;

if RegQueryInfoKey(Key, nil, nil, nil, nil, nil, nil, nil, @MaxValueNameLen, nil,
    nil, nil) = ERROR_SUCCESS then
 begin
 if MaxValueNameLen > 0 then
   begin
     Size:=MaxValueNameLen+1;
     GetMem(Buf,Size * SizeOf(KOLChar) );
     i:=0;
     while RegEnumValue(Key,i,buf,Size,nil,nil,nil,nil) <> ERROR_NO_MORE_ITEMS do
     begin
      List.Add(KOLString(Buf));
      //Size:=MaxValueNameLen+1;
      inc(i);
     end;

     FreeMem(Buf {,MaxValueNameLen + ... system always knows how long buffer is});
   end; // if MaxValueNameLen
  Result:=true;
 end; // if RegQueryInfoKey

end;
{$ENDIF}

program Test;

uses
 Windows, Messages, KOL;

var
 RegKey: HKEY;
 StrList: PKOLStrList;
 Counter: Integer;

begin
 StrList := NewKOLStrList;
 RegKey := RegKeyOpenCreate(HKEY_CURRENT_USER,'Software\KOL Test\'+Date2StrFmt('yyMMdd',Now)+Time2StrFmt('HHmmss',Now));
 try
   for Counter := 1 to 26 do
     RegKeySetStr(RegKey,StrRepeat(Chr($60+Counter),Counter),Int2Str(Counter));
   if RegKey <> 0 then
     RegKeyGetValueNames(RegKey,StrList);
   MsgOK(StrList.Text);
 finally
   RegKeyClose(RegKey);
   StrList.Free;
 end;
end.

function RegKeyGetStrEx( Key: HKey; const ValueName: KOLString; ExpandEnvVars: Boolean ): KOLString;
var dwType, dwSize: DWORD;
   Buffer, Buffer2: PKOLChar;
   Sz: Integer;
   function Query: Boolean;
   begin
     Result := RegQueryValueEx( Key, PKOLChar( ValueName ), nil, @dwType,
               Pointer( Buffer ), @dwSize ) = ERROR_SUCCESS;
   end;
begin
 Result := '';
 if Key = 0 then Exit;
 dwSize := 0;
 Buffer := nil;
 if not Query or ((dwType <> REG_SZ) and (dwtype <> REG_EXPAND_SZ)) then Exit;
 GetMem( Buffer, dwSize * Sizeof( KOLChar ) );
 if Query then
 begin
   if (dwtype = REG_EXPAND_SZ) and (ExpandEnvVars) then
   begin
     Sz := ExpandEnvironmentStrings(Buffer,nil,0);  // bug in size detection! sometimes we get an additional 2 bytes at the end...
     GetMem(Buffer2,Sz * Sizeof( KOLChar ));                            //
     ExpandEnvironmentStrings(Buffer, Buffer2, Sz); //
     Result:=Buffer2;                               //
     FreeMem(Buffer2);                              //
   end
     else
   Result := Buffer;
 end;
 FreeMem( Buffer );
end;

{$IFDEF OLD_REGKEYGETSUBKEYS}
//-----------------------------------------------
// functions by Valerian Luft <luft@valerian.de>
//-----------------------------------------------
//[function RegKeyGetSubKeys]
function RegKeyGetSubKeys( const Key: HKEY; List: PKOLStrList) : Boolean;
var
 I, Size, NumSubKeys, MaxSubKeyLen : DWORD;
 KeyName: KOLString;
begin
 Result := False;
 List.Clear ;
 if RegQueryInfoKey(Key, nil, nil, nil, @NumSubKeys, @MaxSubKeyLen, nil, nil, nil, nil,
nil, nil) = ERROR_SUCCESS then
   begin
     if NumSubKeys > 0 then begin
       for I := 0 to NumSubKeys-1 do
       begin
         Size := MaxSubKeyLen+1;
         SetLength(KeyName, Size);
         FillChar(KeyName[1],Size,#0);
         RegEnumKeyEx(Key, I, @KeyName[1], Size, nil, nil, nil, nil);
         KeyName := Trim(KeyName);
         List.Add(KeyName);
       end;
     end;
     Result:= True;
 end;
end;
{$ELSE} // new (faster) version by Alex Shyshko (Psychedelic)
function RegKeyGetSubKeys(const Key: HKEY; List: PKOLStrList) : Boolean;
var
 i, MaxSubKeyLen, Size: DWORD;
 Buf: PKOLChar;
begin
Result:=false;
List.Clear;

if RegQueryInfoKey(Key, nil, nil, nil, nil, @MaxSubKeyLen, nil, nil, nil, nil,
    nil, nil) = ERROR_SUCCESS then
 begin
 if MaxSubKeyLen > 0 then
   begin
     Size:=MaxSubKeyLen + 1;
     GetMem(Buf,Size * SizeOf(KOLChar) );
     i:=0;

     while RegEnumKeyEx(Key,i,buf,Size,nil,nil,nil,nil) <> ERROR_NO_MORE_ITEMS do
     begin
      List.Add(KOLString(Buf));
      Size:=MaxSubKeyLen + 1;
      inc(i);
     end;

     FreeMem(Buf{,MaxSubKeyLen + 1});
   end; // if MaxSubKeyLen
  Result:=true;
 end; // if RegQueryInfoKey

end;
{$ENDIF}