Question

这是我的代码：我点击鼠标右键，然后选择test1代码创建一个JLabel并将其放在那个位置。

    public class Test extends JFrame {
       int x;
       int y;
       JPopupMenu menu = new JPopupMenu("Popup");

       class MyLabel extends JLabel {
          public MyLabel(String text) {
          super(text);
          addMouseListener(new PopupTriggerListener());
       }

class PopupTriggerListener extends MouseAdapter {
  public void mousePressed(MouseEvent ev) {
    if (ev.isPopupTrigger()) {
      menu.show(ev.getComponent(), ev.getX(), ev.getY());
      x = ev.getX();
      y = ev.getY();
    }
  }

  public void mouseReleased(MouseEvent ev) {
    if (ev.isPopupTrigger()) {
      menu.show(ev.getComponent(), ev.getX(), ev.getY());
      x = ev.getX();
      y = ev.getY();
    }
  }

          public void mouseClicked(MouseEvent ev) {
          }
        }
      }

  JLabel label = new MyLabel("right-click");

    public Test() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JMenuItem item = new JMenuItem("Test1");
        item.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e) {

            System.out.println("Menu item Test1");
            JLabel newLabel = new JLabel("test");
            label.add(newLabel);
            newLabel.setBounds(x, y, 40, 10);
                  }
                });
        menu.add(item);

        item = new JMenuItem("Test2");
        item.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e) {
            System.out.println("Menu item Test2");
          }
        });
        menu.add(item);

        getContentPane().add(label);
        pack();
        setSize(300, 100);
      }

      public static void main(String[] args) {
        new Test().setVisible(true);
      }

但我不知道之后，我如何访问该标签（例如，修改他们的文本）。如果用户用右键单击它并选择“删除”，我也想删除那些标签，但在actionPerformed代码中netbeans不要让我添加另一个actionListener ..任何人都可以帮助我吗？感谢

Answer 1

所有更改都在Test构造函数中：

public Test() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    // Change the name here from "Test1" to whatever you want
    JMenuItem item = new JMenuItem("Test1");
    item.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            System.out.println("Menu item Test1");
            JLabel newLabel = new JLabel("test");
            label.add(newLabel);
            newLabel.setBounds(x, y, 40, 10);
        }
    });
    menu.add(item);

    // Change the name here from "Test2" to whatever you want
    item = new JMenuItem("Test2");
    item.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            System.out.println("Menu item Test2");
        }
    });
    menu.add(item);

    // Implement a "Delete" option
    item = new JMenuItem("Delete");
    item.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            System.out.println("Menu item Delete");
            // Get the component at the mouse coordinates
            Component comp = label.getComponentAt(x, y);
            // If the component is a JLabel, delete it
            if (comp instanceof JLabel) {
                label.remove(comp);
                // Repaint the screen to remove the label
                repaint();
            }
        }
    });
    menu.add(item);

    getContentPane().add(label);
    pack();
    setSize(300, 100);
}

如何访问以序列化方式创建的对象？

1 个答案: