[Nyctos Kasignete]

Вот метод вертикальной прокрутки в ScrollBox... =)

Код:

type
  TForm1 = class(TForm)
    ScrollBox1: TScrollBox;
    Image1: TImage;
    // ...............
   private
    { Private declarations }
    procedure WMMOUSEWHEEL(var Msg: TMessage); message WM_MOUSEWHEEL;
  public
    { Public declarations }
  end;

......................

procedure TForm1.WMMOUSEWHEEL(var Msg: TMessage);
var
  zDelta: Integer;
begin
  inherited;
  if WindowFromPoint(Mouse.CursorPos) <> ScrollBox1.Handle then Exit;
  if Msg.WParam < 0 then zDelta := -10 else zDelta := 10;
  with ScrollBox1 do
  begin
    if ((VertScrollBar.Position = 0) and
        (zDelta > 0)) or
       ((VertScrollBar.Position = VertScrollBar.Range - ClientHeight) and
        (zDelta < 0)) then Exit;
    ScrollBy(0, zDelta);
    VertScrollBar.Position := VertScrollBar.Position - zDelta;
  end;
end;