Zugriff von Klasse auf Ereignis fremder Komponente

[Stevie]

Die musst SetMethoden für deine MenuItems erstellen:

Delphi-Quellcode:

interface
{...}
type
  TMyTreeView = class(TTreeView)
  private
    FCopyMenuItem: TMenuItem;
    FOldCopyOnClick: TNotifyEvent;
    procedure SetCopyMenuItem(const Value: TMenuItem);
    procedure MyMenuItemOnClick(Sender: TObject);
  published
    property CopyMenuItem: TMenuItem read FCopyMenuItem write SetCopyMenuItem;
  end;

implementation

procedure TMyTreeView.MyMenuItemOnClick(Sender: TObject);
begin
  {...}
end;

procedure TMyTreeView.SetCopyMenuItem(const Value: TMenuItem);
begin
  if FCopyMenuItem <> Value then
  begin
    if Assigned(FCopyMenuItem) then
      // alten Eventhandler wieder zuweisen
      FCopyMenuItem.OnClick := FOldCopyOnClick;

    // MenuItem zuweisen
    FCopyMenuItem := Value;

    if Assigned(FCopyMenuItem) then
    begin
      // alten Eventhandler "retten"
      FOldCopyOnClick := FCopyMenuItem.OnClick;
      // eigenen Eventhandler zuweisen
      FCopyMenuItem.OnClick := MyMenuItemOnClick;
    end;

    if Value <> nil then
      Value.FreeNotification(Self);
  end;
end;

{...}