안녕하세요. 최용일입니다.

뭐 여러가지 방법이 있겠지만....

걍 Window Procedure를 바꾸어 버리세요....

type
    TForm2 = class(TForm)
        RichEdit1: TRichEdit;
        RichEdit2: TRichEdit;
        Button1: TButton;
        procedure FormCreate(Sender: TObject);
      procedure FormDestroy(Sender: TObject);
    private
        SaveWndProc1: TWndMethod;
        SaveWndProc2: TWndMethod;
        procedure Re1WndProc(var Message: TMessage);
        procedure Re2WndProc(var Message: TMessage);
    public
    end;

var
  Form2: TForm2;

implementation

{$R *.DFM}

{ TForm2 }

procedure TForm2.FormCreate(Sender: TObject);
begin
    SaveWndProc1 := RichEdit1.WindowProc;
    SaveWndProc2 := RichEdit2.WindowProc;
    RichEdit1.WindowProc := Re1WndProc;
    RichEdit2.WindowProc := Re2WndProc;
end;

procedure TForm2.Re1WndProc(var Message: TMessage);
begin
  if (Message.Msg = WM_HSCROLL) or (Message.Msg = WM_VSCROLL) then
  begin
      if (Message.Result <> RichEdit1.Handle) then
      begin
          Message.Result := RichEdit2.Handle;
          Re2WndProc(Message);
      end;
  end;

  SaveWndProc1(Message);
end;

procedure TForm2.Re2WndProc(var Message: TMessage);
begin
  if (Message.Msg = WM_HSCROLL) or (Message.Msg = WM_VSCROLL) then
  begin
      if (Message.Result <> RichEdit2.Handle) then
      begin
          Message.Result := RichEdit1.Handle;
          Re1WndProc(Message);
      end;
  end;

  SaveWndProc2(Message);
end;

^^ 항상 즐코하세요...

내용없습니당