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