我如何查找秋千是否打开了窗户

一个简单的窗口Manger并不是很棘手，您需要的只是

• WindowListener跟踪正在监听的Windows
• 创建窗口并注册侦听器的已定义位置
• 使Windows在关闭时不执行任何操作，并让侦听器负责是否要关闭的决定（除最后一个以外的所有操作都将这样做）

一些片段：

    // the listener (aka: WindowManager)    WindowListener l = new WindowAdapter() {        List<Window> windows = new ArrayList<Window>();        @Override        public void windowOpened(WindowEvent e) { windows.add(e.getWindow());        }        @Override        public void windowClosing(WindowEvent e) { if (windows.size() > 1) {     windows.remove(e.getWindow());     e.getWindow().dispose(); }        }    };    // create the first frame    Jframe frame = createframe(l);    frame.setVisible(true);// a method to create a new window, config and add the listener    int counter = 0;    private Jframe createframe(final WindowListener l) {        Action action = new AbstractAction("open new frame: " + counter) { @Override public void actionPerformed(ActionEvent e) {     Jframe frame = createframe(l);     frame.setVisible(true); }        };        Jframe frame = new Jframe("someframe " + counter++);        frame.setDefaultCloseOperation(Jframe.DO_NOTHING_ON_CLOSE);        frame.add(new JButton(action));        frame.addWindowListener(l);        frame.pack();        frame.setLocation(counter * 20, counter * 10);        return frame;    }