Question

在我的课程中，我想向主要的JPanel添加其他JPanel obj在子类中创建的dinamically并捕获鼠标事件，确切地知道女巫obj生成它。我尝试通过创建子类DoSquare（JPanel扩展），添加侦听器，创建objs并绘制该子类的Graphics来做到这一点，但是当我运行程序并单击创建的一个DoSquare obj时，e.getSource（）总是返回SubObj对象而不是单击的元素。如何区分Listener事件中选择的组件？

这是我的代码：

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class SubObj extends JPanel {

 Listener listener = new Listener();
 DoSquare firstQ = new DoSquare(100, 50);
 DoSquare secondQ = new DoSquare(200, 70);

 public static void main(String[] args) {

    JFrame panel = new JFrame();
    SubObj content = new SubObj();
    panel.setContentPane(content);
    panel.setFocusable(true);
    panel.setSize(400, 400);
    panel.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    panel.setVisible(true);

 }

 SubObj() {
    addMouseListener(listener);
    addFocusListener(listener);

 }

 public void paintComponent(Graphics g) {
    super.paintComponent(g);


    firstQ.draw(g, Color.BLACK);
    secondQ.draw(g, Color.CYAN);
 }

 private class DoSquare extends JPanel {

    private int coordX;
    private int coordY;
    Listener squareLis = new Listener();

    DoSquare(int X, int Y) {
        addMouseListener(squareLis);
        addFocusListener(squareLis);
        coordX = X;
        coordY = Y;
    }

    void draw(Graphics g, Color c) { // Draw the square

        g.setColor(c);
        g.fillRect(coordX, coordY, 50, 50);
    }


}

 public class Listener implements MouseListener, FocusListener {
    public void mouseClicked(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
    public void mousePressed(MouseEvent e) {
        System.out.println(e.getSource());

    }
    public void mouseReleased(MouseEvent e) {}

    public void focusGained(FocusEvent e) {}
    public void focusLost(FocusEvent e) {}
 }

}

提前致谢

AM

Answer 1

在SubObj班级的构造函数中，您应该执行以下操作：

SubObj() {
    firstQ.addMouseListener(listener);
    secondQ.addFocusListener(listener);
}

并删除squareLis课程中的DoSquare变量。

<强>更新

public class SubObj extends JPanel {

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                SubObj content = new SubObj();
                frame.setContentPane(content);
                frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
                frame.pack();
                frame.setVisible(true);
            }
        });
    }

    SubObj() {
        MouseAdapter mouseAdapter = new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                System.out.println(e.getSource());
                System.out.println("click from " + ((TestPanel) e.getSource()).getId());
            }
        };

        JPanel testPanel1 = new TestPanel("1");
        testPanel1.setPreferredSize(new Dimension(200, 200));
        testPanel1.setBackground(Color.BLACK);
        testPanel1.addMouseListener(mouseAdapter);
        add(testPanel1);

        JPanel testPanel2 = new TestPanel("2");
        testPanel2.setPreferredSize(new Dimension(100, 100));
        testPanel2.setBackground(Color.RED);
        testPanel2.addMouseListener(mouseAdapter);
        add(testPanel2);
    }

    private class TestPanel extends JPanel {
        private String id;

        TestPanel(String id) {
            this.id = id;     
        }

        public String getId() {
            return id;
        }
    }
}

我上面写的代码等同于你想要实现的代码，它以你想要的方式工作。我不会使用您的代码，因为我不确定您希望它是什么。我的代码用于演示两个子面板在点击时如何响应鼠标事件，这是我们关注此问题的重点。

来自子类obj的Java陷阱事件

1 个答案: