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我正在尝试用两个简单的按钮创建一个 JPanel。第一个按钮RoachComponent使面板中的组件数量增加一倍。第二个按钮将清除所有蟑螂。

现在,我的大部分程序都在工作,但有一个相当严重的问题。每次点击只添加一个蟑螂,即使它应该添加几千只蟑螂。我已经测试了我能想到的所有东西,但它仍然让我望而却步。即使我手动添加两只蟑螂,也只显示一只。这是我的主要功能中的代码。我有 99% 的把握在代码的所有其他部分中一切都是正确的,尽管我可以在需要时发布它。

final JFrame frame = new JFrame();
    final JPanel panel = new JPanel();
    // Button to create a new roach
    JButton button = new JButton("New Roach");

    final RoachPopulation roachPopulation = new RoachPopulation(2);

    // The label for displaying the results
    final JLabel label = new JLabel("Population: " + roachPopulation.getPopulation());

    // ActionListener class
    class doubleListener implements ActionListener {
        public void actionPerformed(ActionEvent event) {

            System.out.println("------------------");
            for (int i = 0; i < roachPopulation.getPopulation(); i++) {
                RoachComponent newRoach = new RoachComponent();
                panel.add(newRoach);
                newRoach.getCoords();
            }
            panel.repaint();
            frame.repaint();
            roachPopulation.doublePopulation();
            label.setText("Population: " + roachPopulation.getPopulation());
            // Showing that there *is* the correct number of roaches in the panel.
            System.out.println(panel.getComponentCount());
        }
    }
    RoachComponent r1 = new RoachComponent();
    RoachComponent r2 = new RoachComponent();
    panel.setLayout(new BorderLayout());
    panel.add(button, BorderLayout.SOUTH);
    panel.add(label, BorderLayout.NORTH);
    panel.add(r1);
    panel.add(r2);
    //panel.add(component, BorderLayout.CENTER);
    frame.add(panel);

    frame.repaint();

    ActionListener doubleListener = new doubleListener();
    button.addActionListener(doubleListener);

    frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);

}
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2 回答 2

6
于 2013-02-01T23:19:46.483 回答
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一个问题是您需要JPanel在添加后重新验证RoachComponent

panel.revalidate();
于 2013-02-01T23:19:28.780 回答