如何捕捉点击滚动条发生的事件

[slyt]

当我点击CheckListBox的滚动条时,想做一定的处理,该写哪个事件啊,或者如何捕捉到也行

[alexanda2000]

type
TForm1 = class(TForm)
CheckListBox1: TCheckListBox;
Button1: TButton;
procedure FormCreate(Sender: TObject);
private
OldWndProc:TWndMethod;
procedure NewWndProc(var Msg:TMessage);Message WM_VSCROLL;
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.NewWndProc(var Msg: TMessage);
begin
if Msg.Msg = WM_VSCROLL then ShowMessage('接收到滚动条消息');
if Assigned(OldWndProc) then
OldWndProc(Msg);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
OldWndProc:=CheckListBox1.WindowProc;
CheckListBox1.WindowProc:=NewWndProc;
end;

[slyt]

xiexie

[alexanda2000]

不好意思,
procedure NewWndProc(var Msg:TMessage);Message WM_VSCROLL;
这一句的Message WM_VSCROLL应该去掉