Question

我对Java比较陌生。我所看到的所有示例在程序中仅具有一种侦听器类型。我想开发一个程序来查看鼠标事件，按钮和其他组件的单击或动作以及键盘事件。该程序以绝对模式进行编码，因为我想准确地放置多边形并能够在其中单击/。以下测试程序开始起作用。

如何使任何按钮正常工作？
在非Swing应用程序中，我看不到任何有关鼠标和按钮事件的问题和答案。

公共类Layout2扩展了JFrame {

public JPanel panel;
public Panel cmds;

JButton btn_test = new JButton("Test");
JLabel lb_test = new JLabel("Object");
JLabel lb_test2 = new JLabel("LB - Test");

Polygon[] poly = new Polygon[3];

public void buildPanel() {
    panel = new JPanel();
    panel.setLayout(null);
    panel.setPreferredSize(new Dimension(1000, 100));

    JButton b1 = new JButton("MC");
    JButton b2 = new JButton("MR");
    JButton b3 = new JButton("MS");
    JButton b4 = new JButton("M+");
    JButton b5 = new JButton("M-");

    //Insets insets = pane.getInsets();
    //Dimension size = b1.getPreferredSize();
    b1.setBounds(5, 5, 52, 42);
    //size = b2.getPreferredSize();
    b2.setBounds(57, 5, 52, 42);
    //size = b3.getPreferredSize();
    b3.setBounds(109, 5, 52, 42);
    b4.setBounds(161, 5, 52, 42);
    b5.setBounds(213, 5, 52, 42);

    panel.add(b1);
    panel.add(b2);
    panel.add(b3);
    panel.add(b4);
    panel.add(b5);

    //JButton btn_test = new JButton("Test");
    btn_test.setBounds(410, 5, 80, 42);
    panel.add(btn_test);

    //JLabel lb_test = new JLabel("Object");
    lb_test.setBounds(550, 5, 120, 42);
    panel.add(lb_test);

    lb_test2.setBounds(100, 5, 80, 42);
    lb_test2.setLocation(100, 10);
    add(lb_test2, BorderLayout.NORTH);

    cmds = new Panel();
    cmds.setLayout(null);
    cmds.setPreferredSize(new Dimension(1000, 100));
    cmds.setBackground(Color.black);
    panel.add(cmds);

    //panel.add(TrianglePanel);
}

private Layout2() {
    //Create and set up the window.

    super("AbsoluteLayoutDemo");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new BorderLayout());

    //Set up the content pane.
    buildPanel();
    add(panel, BorderLayout.SOUTH);
    add(new TrianglePanel(), BorderLayout.CENTER);

    //Size and display the window.
    setSize(1280, 1000);

    setVisible(true);
}

class TrianglePanel extends JPanel implements MouseListener {

    public TrianglePanel() {
        //Create triangle

        poly[0] = new Polygon();
        poly[0].addPoint(150, 300);
        poly[0].addPoint(100, 200);
        poly[0].addPoint(200, 200);

        poly[1] = new Polygon();
        poly[1].addPoint(125, 25);
        poly[1].addPoint(145, 120);
        poly[1].addPoint(180, 90);
        poly[1].addPoint(200, 145);
        poly[1].addPoint(200, 25);

        poly[2] = new Polygon();
        poly[2].addPoint(350, 300);
        poly[2].addPoint(300, 200);
        poly[2].addPoint(400, 200);

        //Add mouse Listener
        addMouseListener(this);

        //Set size to make sure that the whole triangle is shown
        setPreferredSize(new Dimension(1000, 800));
    }

    public void paintComponent(Graphics g) {
        Graphics2D g2d = (Graphics2D) g;

        g2d.setPaint(Color.red);
        //g2d.fill(triangle);
        g2d.draw(poly[0]);
        g2d.draw(poly[2]);

        g2d.setPaint(Color.blue);
        g2d.fill(poly[1]);
        g2d.draw(poly[1]);

        g2d.setFont(new Font("Courier", Font.PLAIN, 16));  //TimesRoman

        g2d.setPaint(Color.yellow);
        g2d.drawString("10", 150, 50);

        g2d.setPaint(Color.blue);
        g2d.fill(poly[1]);

        g2d.setPaint(Color.yellow);
        g2d.drawString("    ", 150, 50);
        g2d.drawString("5", 150, 50);

    }

    //Required methods for MouseListener, though the only one you care about is click
    @Override
    public void mousePressed(MouseEvent e) {
    }

    @Override
    public void mouseReleased(MouseEvent e) {
    }

    @Override
    public void mouseEntered(MouseEvent e) {
    }

    @Override
    public void mouseExited(MouseEvent e) {
    }

public void btn_testActionPerformed（java.awt.event.MouseEvent evt）{//java.awt.event.ActionEvent // TODO：在此处添加您的处理代码： System.out.println（“ btn_test2”）; }

    @Override
    public void mouseClicked(MouseEvent e) {
        Point p = e.getPoint();
        for (int pn = 0; pn < 3; pn++) {
            if (poly[pn].contains(p)) {
                lb_test.setText("Polygon: " + pn);
                lb_test2.setText("Polygon: " + pn);
            }
        }
    }
}

public static void main(String[] args) {

    new Layout2();
}

}

如何使用多种侦听器类型

0 个答案: