constWM_THEMECHANGED = $031A; type
TForm1 = class
(TForm) {...} private
public
procedure
WMTHEMECHANGED(var
Msg: TMessage); message
WM_THEMECHANGED; end
; {...} implementation
{...} procedure
TForm1.WMTHEMECHANGED(var
Msg: TMessage); begin
Label1.Caption := 'Theme changed'; Msg.Result := 0; end
;