Question

我想在GUI中有一个菜单栏。菜单不可见。

public class GUI extends JPanel implements ItemListener{

final static String RUN_TEST = "Test 4G";
final static String SETTINGS = "Settings";
JPanel p;
JPanel cards = new JPanel(new CardLayout());
public GUI(){
    JFrame window = new JFrame();

    TestRun runTest = new TestRun();

    cards.add(runTest , RUN_TEST);
    cards.add(runTest , SETTINGS);

    CardLayout cl = (CardLayout)(cards.getLayout());
    cl.show(cards, RUN_TEST);
    window.setContentPane(cards);

    window.pack();
    window.setVisible(true);
}

@Override
public void itemStateChanged(ItemEvent evt) {
    CardLayout cl = (CardLayout)(cards.getLayout());
    cl.show(cards, (String)evt.getItem());
}
 }

如何向用户显示菜单“Test 4G”和“settings”以便他们可以更改JPanel？谢谢你的帮助

Answer 1

这是在JMenuBar中使用JFrame和JPopupMenu JPanel中使用public class MainFrame extends JFrame { final static String RUN_TEST = "Test 4G"; final static String SETTINGS = "Settings"; private JPanel viewPanel = new JPanel(); public MainFrame() throws HeadlessException { super("MainFrame"); cretaeGUI(); } private void cretaeGUI() { setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); setLayout(new BorderLayout()); setJMenuBar(cretaeMenuBar()); setMinimumSize(new Dimension(800, 600)); viewPanel.setLayout(new CardLayout()); viewPanel.add(new Test4GView(this), RUN_TEST); viewPanel.add(new SettingsView(this), SETTINGS); add(viewPanel, BorderLayout.CENTER); pack(); setLocationRelativeTo(null); } private JMenuBar cretaeMenuBar() { JMenuItem testMenuItem = new JMenuItem("Test 4G"); testMenuItem.addActionListener(this::showTest4GView); JMenuItem settingsMenuItem = new JMenuItem("Settings"); settingsMenuItem.addActionListener(this::showSettingsView); JMenu viewMenu = new JMenu("View"); viewMenu.add(testMenuItem); viewMenu.add(settingsMenuItem); JMenuBar menuBar = new JMenuBar(); menuBar.add(viewMenu); return menuBar; } private void showView(String name) { ((CardLayout)viewPanel.getLayout()).show(viewPanel, name); } public void showTest4GView(ActionEvent event) { showView(RUN_TEST); } public void showSettingsView(ActionEvent event) { showView(SETTINGS); } public static void main(String[] args) { SwingUtilities.invokeLater(() -> new MainFrame().setVisible(true)); } }的示例。

public class Test4GView extends JPanel {

    private MainFrame mainFrame;

    public Test4GView(MainFrame mainFrame) {
        this.mainFrame = mainFrame;

        add(new JLabel("Test 4G"));

        addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                showPopupMenu(e);
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                showPopupMenu(e);
            }

            private void showPopupMenu(MouseEvent e) {
                if(!e.isPopupTrigger()) {
                    return;
                }

                JMenuItem showSettingsView = new JMenuItem("Settings");
                showSettingsView.addActionListener(mainFrame::showSettingsView);

                JPopupMenu popupMenu = new JPopupMenu();
                popupMenu.add(showSettingsView);

                popupMenu.show(e.getComponent(), e.getX(), e.getY());
            }
        });
    }
}

public class SettingsView extends JPanel {

    private MainFrame mainFrame;

    public SettingsView(MainFrame mainFrame) {
        this.mainFrame = mainFrame;

        add(new JLabel("Settings"));

        addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                showPopupMenu(e);
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                showPopupMenu(e);
            }

            private void showPopupMenu(MouseEvent e) {
                if(!e.isPopupTrigger()) {
                    return;
                }

                JMenuItem showSettingsView = new JMenuItem("Test 4G");
                showSettingsView.addActionListener(mainFrame::showTest4GView);

                JPopupMenu popupMenu = new JPopupMenu();
                popupMenu.add(showSettingsView);

                popupMenu.show(e.getComponent(), e.getX(), e.getY());
            }
        });
    }
}

这些都是观点

"../node_modules/bootstrap/dist/css/bootstrap.min.css"

Java - 从CardLayout显示菜单

1 个答案: