请你写一个程序实现动态的球在窗内运动,碰到边框时进行反弹
时间: 2024-03-10 09:47:40 浏览: 31
好的,以下是一个简单的程序实现动态的球在窗内运动,碰到边框时进行反弹的效果:
```java
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class BallTest extends JPanel {
public static final int APPLICATION_WIDTH = 400;
public static final int APPLICATION_HEIGHT = 600;
private int ballX, ballY;
private static final int BALL_RADIUS = 10;
private static final int DELAY = 20;
private Timer ballMoveTimer;
private double vx, vy;
public BallTest() {
ballX = APPLICATION_WIDTH / 2;
ballY = APPLICATION_HEIGHT / 2;
Random rgen = new Random();
vx = rgen.nextDouble() * 2 + 1;
vy = rgen.nextDouble() * 2 + 1;
if (new Random().nextBoolean()) vx = -vx;
if (new Random().nextBoolean()) vy = -vy;
ActionListener listener = new TimePainter();
ballMoveTimer = new Timer(DELAY, listener);
ballMoveTimer.start();
setPreferredSize(new Dimension(APPLICATION_WIDTH, APPLICATION_HEIGHT));
setBackground(Color.white);
}
public void paintComponent(Graphics page) {
super.paintComponent(page);
drawBall(page);
}
private void drawBall(Graphics page) {
Graphics2D pages = (Graphics2D) page;
Ellipse2D currentE = new Ellipse2D.Double(ballX, ballY, BALL_RADIUS, BALL_RADIUS);
pages.setColor(Color.BLACK);
pages.fill(currentE);
}
class TimePainter implements ActionListener {
public void actionPerformed(ActionEvent event) {
if (ballX + BALL_RADIUS > APPLICATION_WIDTH || ballX < 0) {
vx = -vx;
}
if (ballY + BALL_RADIUS > APPLICATION_HEIGHT || ballY < 0) {
vy = -vy;
}
ballX += vx;
ballY += vy;
repaint();
}
}
public static void main(String[] args) {
JFrame frame = new JFrame("Ball Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
BallTest panel = new BallTest();
frame.getContentPane().add(panel);
frame.pack();
frame.setVisible(true);
}
}
```
程序窗口内会绘制一个球,球的运动方向和速度是随机生成的,碰到边框时会进行反弹。程序中使用了一个 `Timer` 类来控制球的运动,每隔一段时间就会触发 `actionPerformed` 方法,在该方法中进行球的位置更新和重绘。