Memo Scrollbar Events

[DeddyH]

Auf die Schnelle aus dem Hut:

Delphi-Quellcode:

type
  TScrollChangeEvent = procedure(Sender: TObject;
    const ScrollCode, Pos: SmallInt) of object;

  TMemo = class(StdCtrls.TMemo)
  private
    FOnHorzScroll: TScrollChangeEvent;
    FOnVertScroll: TScrollChangeEvent;
    procedure WMHScroll(var Msg: TWMHScroll); message WM_HSCROLL;
    procedure WMVScroll(var Msg: TWMVScroll); message WM_VSCROLL;
  public
    property OnHorzScroll: TScrollChangeEvent read FOnHorzScroll write FOnHorzScroll;
    property OnVertScroll: TScrollChangeEvent read FOnVertScroll write FOnVertScroll;
  end;

  TForm1 = class(TForm)
    Memo1: TMemo;
    procedure FormCreate(Sender: TObject);
  private
    { Private-Deklarationen }
    procedure DoOnHorzScroll(Sender: TObject; const ScrollCode, Pos: SmallInt);
    procedure DoOnVertScroll(Sender: TObject; const ScrollCode, Pos: SmallInt);
  public
    { Public-Deklarationen }
  end;

...

procedure TMemo.WMHScroll(var Msg: TWMHScroll);
begin
  if Assigned(FOnHorzScroll) then
    FOnHorzScroll(self, Msg.ScrollCode, Msg.Pos);
  inherited;
end;

procedure TMemo.WMVScroll(var Msg: TWMVScroll);
begin
  if Assigned(FOnVertScroll) then
    FOnVertScroll(self, Msg.ScrollCode, Msg.Pos);
  inherited;
end;

procedure TForm1.DoOnHorzScroll(Sender: TObject; const ScrollCode,
  Pos: SmallInt);
begin
  ShowMessage('Horizontal: ' + IntToStr(Pos));
end;

procedure TForm1.DoOnVertScroll(Sender: TObject; const ScrollCode,
  Pos: SmallInt);
begin
  ShowMessage('Vertikal: ' + IntToStr(Pos));
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Memo1.OnHorzScroll := DoOnHorzScroll;
  Memo1.OnVertScroll := DoOnVertScroll;
end;