如何拦截滚动条消息

[shandong1]

各位大虾，我是用c++ builder开发的一个程序，应当和Delphi差不多吧！我如何拦截一个scrollbox控件的滚动消息呢？求救呀！

[zxblue]

unit Unit1;

interface

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

type
TForm1 = class(TForm)
Button1: TButton;
Memo1: TMemo;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

TMyScrollBar = class(TScrollBar)
private
i : Integer;
procedure CNHScroll(var Message: TWMHScroll); message CN_HSCROLL;
public
constructor Create(AOwner: TComponent); override;
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

{ TMyScrollBar }

procedure TMyScrollBar.CNHScroll(var Message: TWMHScroll);
begin
TForm1(parent).Memo1.Lines.Append(IntToStr(i));
i := i + 1;
inherited;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
myScrollBar :TMyScrollBar;
begin
myScrollBar := TMyScrollBar.Create(Self);
myScrollBar.Parent := Self;
myScrollBar.Show;
end;

constructor TMyScrollBar.Create(AOwner: TComponent);
begin
inherited;
i := 1;
Max := 10;
end;

end.