Code:

{ You maybe have to access  just a part of a GUID. }

{ Const for the function Format(...) }

const

fsGUID: string = 'D1: $%s'#13#10'D2: $%s'#13#10'D3: $%s'#13#10 +

   'D4: $%s $%s $%s $%s $%s $%s $%s $%s';

fsGUIDParts: string = 'D%d:%s';

// Type for the GUID part to be shown

type

TGUIDPART = (guidp_NoFormat, guidp_All, guidp_D1,

   guidp_D2, guidp_D3, guidp_D4);

{ This GUIDToStringEx function give you the full GUID string

according with then format string FStr (you can change it !!!) }

function GUIDToStringEx(Guid: TGuid; FStr: string): string; overload;

begin

Result := Format(FStr,

   [IntToHex(GUID.D1, 8),

   IntToHex(GUID.D2, 4),

   IntToHex(GUID.D3, 4),

   IntToHex(GUID.D4[0], 2),

   IntToHex(GUID.D4[1], 2),

   IntToHex(GUID.D4[2], 2),

   IntToHex(GUID.D4[3], 2),

   IntToHex(GUID.D4[4], 2),

   IntToHex(GUID.D4[5], 2),

   IntToHex(GUID.D4[6], 2),

   IntToHex(GUID.D4[7], 2)

   ]);

end;

{ This GUIDToStringEx function give you the part of the GUID

to be shown, according to the part type GUIDPart }

function GUIDToStringEx(Guid: TGuid; Part: TGUIDPART): string; overload;

var

i: Integer;

S: string;

begin

S := '';

case Part of

   guidp_NoFormat: S := GUIDToString(Guid);

   guidp_All:      S := GUIDToStringEx(Guid, fsGUID);

   guidp_D1:       S := Format(fsGUIDParts, [1, ' $' + IntToHex(GUID.D1, 8)]);

   guidp_D2:       S := Format(fsGUIDParts, [2, ' $' + IntToHex(GUID.D2, 4)]);

   guidp_D3:       S := Format(fsGUIDParts, [3, ' $' + IntToHex(GUID.D3, 4)]);

   guidp_D4:

     begin

       for i := 0 to 7 do S := S + ' $' + IntToHex(GUID.D4[i], 2);

       S := Format(fsGUIDParts, [4, S]);

     end;

   else

     S := '?';

end;

Result := S;

end;

{ How to use the different GUIDToStringEx functions }

procedure TForm1.Button1Click(Sender: TObject);

var

NewGUID: TGUID;

begin

{ Create a new GUID }

NewGUID := StringToGUID(CreateClassID);

{ Standard formated GUID string }

label1.Caption := GUIDToStringEx(NewGUID, guidp_NoFormat) +

   #13#10 +

   { Full formated GUID string acc. with fsGUID}

   GUIDToStringEx(NewGUID, fsGUID) +

   #13#10 +

   { Full formated GUID string with default formating}

   GUIDToStringEx(NewGUID, guidp_All) +

   #13#10 +

   { Part D3 of the GUID only }

   GUIDToStringEx(NewGUID, guidp_D3);

end;