Java Swing简单动画

Question

我在一个简单的动画程序上遇到了麻烦(是的，这是家庭作业)。该问题要求我们在 500X500 窗口上随机创建 100 个 Particle 类对象，并使用 Swing 计时器移动它们。这是我遇到的问题，所创建的粒子似乎不是随机的，但它们沿对角轴对齐，我无法找到逻辑错误，非常感谢您的帮助。这是一个屏幕截图，应该可以清楚地说明这一点。 http://i57.tinypic.com/qswbix.jpg

我还在帖子末尾发布了家庭作业问题，以防有人发现我的问题难以理解。谢谢您的帮助

public class ParticleFieldWithTimer extends JPanel{
    private ArrayList<Particle> particle = new ArrayList<Particle>();
    Timer timer; 
    boolean b; 
      public ParticleFieldWithTimer (){
       this.setPreferredSize(new Dimension(500,500));


    for(int i = 0; i < 100; i++) { 
        particle.add(new Particle());
    }


    timer = new Timer(40, new ActionListener() 
    {
        @Override
        public void actionPerformed(ActionEvent ae) {
            for (Particle p : particle) {                   
                p.move();                   
            }
            repaint();              
            }           
    });
    timer.start();  

}
   public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setColor(Color.RED);

        for (Particle p : particle) {
        double temp1 = p.getX();
        double temp2 = p.getX();
        int tempX = (int) temp1;
        int tempY = (int) temp2;
        g2.fillRect(tempX, tempY, 3, 3);
        }           

    }
   public static void main(String[] args) {
        final JFrame f = new JFrame("ParticleField");
        final ParticleFieldWithTimer bb = new ParticleFieldWithTimer();
        f.setLayout(new FlowLayout());
        f.add(bb);
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent we) {
                try {
                    bb.finalize();
                } catch (Throwable e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

                f.dispose();
            }
        });
        f.pack();
        f.setVisible(true);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

这是粒子类

 public class Particle {
private int x , y ;

Random r = new Random();

public Particle () {

    x = r.nextInt(500);
    y = r.nextInt(500);

}
public int getX() {
    return x;
}
public int getY() {
    return y;
}
public void move() {

    x += r.nextBoolean() ? 1 : - 1;
    y += r.nextBoolean() ? 1 : - 1;
    System.out.println("x : " + x+" y: " + y);
}



 }

Create a class Particle that has two double fields x and y, a constructor that initializes these fields to random values between 0 and 500, methods getX and getY that return their values, and a method void move() that randomly adds or subtracts one to each of the values of x and y. (The quantities added to x and y are two separate random numbers.) Next, create a class ParticleFieldWithTimer that extends JPanel. This class should prefer to be 500 * 500 pixels in size. Its constructor should first fill an ArrayList field with 100 Particle objects, then start a Swing Timer that ticks 25 times a second. At each tick, the action listener should first call the method move for each particle, and then call repaint. The paintComponent method of ParticleFieldWithTimer should draw each particle as a 3*3 rectangle to its current coordinates.

Answer 1

在paintComponent方法中，

替换

double temp2 = p.getX();

与

double temp2 = p.getY();

祝你好运。