In C I have:

	move = gtk_menu_item_new_with_label (name);
	g_signal_connect(G_OBJECT(move), "activate", G_CALLBACK(MoveToNotepadCB), np);

In D I have tried:

auto move = new MenuItem (name);
		Signals.connectData(view, "activate", &selectNotepad, &selectNotepad, null, ConnectFlags.SWAPPED);