Question

这是我的问题，我无法使用鼠标移动Rectangle2D变量rect移动。我究竟做错了什么？也许我不明白MouseListener是如何运作的。

public class CreppyRectangle extends JComponent {
private int viteza = 15;
private int yPosL = 100;
Rectangle2D rect;
Graphics2D g3d;
int lungimea = 40;
int latimea = 10;
int x = 0;
int y = 100;
public static void main(String[] args) {
    new CreppyRectangle();
}

public CreppyRectangle() {
    addMouseListener(new MouseAdapter() {
        public void mousePressed(MouseEvent e) {

        }
        public void mouseReleased(MouseEvent e) {

        }
     });
    addMouseMotionListener(new MouseAdapter() {
        public void mouseDragged(MouseEvent e) {
            yPosL = e.getX();

            repaint(x, e.getX(), latimea, lungimea);
            System.out.println(e.getX());
        }
    });

    EventQueue.invokeLater(new Runnable() {
        @Override
        public void run() {
            JFrame frame = new JFrame("Testing");
            final TestPane misha = new TestPane(Color.BLACK);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.add(misha);
            frame.pack();
            frame.setLocationRelativeTo(null);
            frame.setVisible(true);
        }
    });
}

public class TestPane extends JPanel {

    private int xPos;
    private int yPos;

    private int size = 10 ;
    private int xDelta = 5;
    private int yDelta = 5;

    public TestPane(Color foreground) {
        setForeground(foreground);

        Timer timer = new Timer(viteza , new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                xPos += xDelta;
                yPos += yDelta;
                if (xPos < 10) {
                    xPos = 10;
                    xDelta *= -1;
                    System.out.println(xDelta);
                } else if (xPos + size > getWidth()) {
                    xPos = getWidth() - size;
                    xDelta *= -1;
                } else if (yPos < 0) {
                    yPos = 0;
                    yDelta *= -1;
                    System.out.println(xDelta);
                } else if (yPos + size > getHeight()) {
                    yPos = getHeight() - size;
                    yDelta *= -1;
                }
                repaint();
            }
        });
        timer.setRepeats(true);
        timer.setCoalesce(true);
        timer.start();
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(500, 200);
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g.create();
        g3d = (Graphics2D) g.create();
        rect = new Rectangle2D.Double(x, yPosL, latimea, lungimea);
        g3d.draw(rect);
        g3d.fill(rect);
        g2d.setColor(getForeground());
        g2d.drawRect(xPos, yPos, size, size);
        g2d.fillRect(xPos, yPos, size, size);
        g2d.dispose();
    }
}
}

Answer 1

基本上，你实际上从未向任何事物添加CreppyRectangle，因此，没有任何东西可以监听鼠标事件。

你的设置有点奇怪。我不知道为什么你要从JComponent延伸，当你应该把所有的逻辑都放在TestPane

时

此外，我认为你不想做yPosL = e.getX()，我想你想尝试yPosL = e.getY()而不是

如何为我的乒乓球获得一个移动的矩形？

1 个答案: