Zwei ListBoxen gleichzeitig scrollen?

[sniper_w]

Hier die notwendigen Änderungen:

Delphi-Quellcode:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TMyListBox = class(TListBox)
  private
    FRef : TCustomListBox;
    procedure WMMouseWheel(var Message: TWMMOUSEWHEEL); message WM_MOUSEWHEEL;
    procedure WMHScroll(var Message: TWMHScroll); message WM_HSCROLL;
    procedure WMVScroll(var Message: TWMVScroll); message WM_VSCROLL;
  public
    constructor Create(AOwner: TComponent); override;
  published
    property Reference : TCustomListBox read FRef write FRef;
  end;
//...
{ TMyListBox }

procedure TMyListBox.WMMouseWheel(var Message: TWMMOUSEWHEEL);
begin
inherited;
if Assigned(FRef) then FRef.TopIndex := TopIndex;
end;