public static FindFriendsWindow GetInstance(String accessToken) { if (FindFriendsWindow.instance == null) { lock (_syncRoot) { if (FindFriendsWindow.instance == null) { FindFriendsWindow.instance = new FindFriendsWindow(accessToken); } } } return FindFriendsWindow.instance; }
private void Window_Closed(object sender, EventArgs e) { instance = null; }