在 Swing 中移动背景图像

Question

你好，我是编程新手，我们有一个项目。我们创建了一个带有移动背景的简单赛车游戏，但我卡在我的代码上，我不知道该怎么做。游戏开始时我需要一个动人的背景，请有人帮助我。我求求T_T

这是我的代码：

public class Game extends JFrame implements KeyListener, ActionListener {

    Random s = new Random();
    int x = 0, y = 50, a = 0, b = 250, f = 900, a1 = 0, b2 = 350, a2 = 0, b3 = 150;
    int Move;
    int value;
    JLabel spriteLabel1 = new JLabel(new ImageIcon("ss.gif"));
    JLabel spriteLabel2 = new JLabel(new ImageIcon("ss.gif"));
    JLabel spriteLabel3 = new JLabel(new ImageIcon("ss.gif"));
    JLabel spriteLabel4 = new JLabel(new ImageIcon("ss.gif"));
    JLabel background = new JLabel(new ImageIcon("geren.png"));
    Timer T1 = new Timer(5000, this);
    Timer T = new Timer(5, this);

    public static void main(String args[]) {
        new Game();
    }

    public Game() {
        Container c = getContentPane();
        c.setLayout(null);
        c.add(spriteLabel1);
        c.add(spriteLabel2);
        c.add(spriteLabel3);
        c.add(spriteLabel4);
        c.add(background);
        background.setBounds(0, 0, 1024, 768);
        addKeyListener(this);
        setSize(1000, 750);
        setVisible(true);
    }

    public void paint(Graphics g) {
        super.paint(g);
        spriteLabel1.setBounds(x, y, 60, 1000);
        spriteLabel2.setBounds(a, b, 60, 800);
        spriteLabel3.setBounds(a1, b2, 60, 500);
        spriteLabel4.setBounds(a2, b3, 60, 650);
    }

    public void keyPressed(KeyEvent e) {
        String k = e.getKeyText(e.getKeyCode());
        if (k.equals("D")) {
            if (a != f) {
                x = x + 15;
                spriteLabel1.setIcon(new ImageIcon("ss.gif"));
                repaint();
                if (x > f) {
                    x = f;
                    spriteLabel1.setIcon(new ImageIcon("ss.gif"));
                    //JOptionPane.showMessageDialog(null,"Congratulations!! 
                    //Sanji wins!","Result",JOptionPane.PLAIN_MESSAGE,
                    //new ImageIcon("evolve sanji.gif"));
                    //System.exit(0);
                }
                repaint();
            }
        }
        T.stop();
    }

    if(k.equals ( 
        "D")) 
    {
        if (x != f) {
            T.start();
            Move = 3;
        }
    }

    public void keyReleased(KeyEvent e) {
    }

    public void keyTyped(KeyEvent e) {
    }

    public void actionPerformed(ActionEvent e) {
        if (Move == 3) {
            a = a + (s.nextInt(3));
            a = a + value;
            if (a > f) {
                a = f;
            }
            spriteLabel2.setIcon(new ImageIcon("ss.gif"));
            spriteLabel2.setBounds(a, b, 100, 800);
        }
        if (a == f) {
            if (Move == 3) {
                a1 = a1 + (s.nextInt(3));
                a1 = a1 + value;
                if (a1 > f) {
                    a1 = f;
                }
                spriteLabel3.setIcon(new ImageIcon("ss.gif"));
                spriteLabel3.setBounds(a1, b2, 100, 500);
            }
            if (Move == 3) {
                a2 = a2 + (s.nextInt(5));
                a2 = a2 + value;
                if (a2 > f) {
                    a2 = f;
                }
                spriteLabel4.setIcon(new ImageIcon("ss.gif"));
                spriteLabel4.setBounds(a2, b3, 100, 650);
            }

        }
    }
}

Answer 1

这里是剧透

这是肉

我看到你做错了几件事：

• 不断创建新图像。只需使用相同的图像即可。

• 我会不使用标签，而是在绘画表面上绘制一个 Image/BufferedImage。

• 忘记两个计时器。你可以用一个来应付。这就是您管理状态的方式。

• 不要在paint方法中做任何逻辑。在您目前的情况下，由于甚至没有画任何东西，您甚至不需要它。在我的示例中，虽然我确实绘制了图像。

• 不要在 JFrame 上绘制并覆盖 paint。在 JPanel 中覆盖 paintComponent 并将该面板添加到框架中。

• 最后，关键成分，使用方法（来自Graphics）——

  public abstract boolean drawImage(Image img,
          int dx1,
          int dy1,
          int dx2,
          int dy2,
          int sx1,
          int sy1,
          int sx2,
          int sy2,
          ImageObserver observer)
  

  你可以得到更好的解释in this post。基本上s点是源图像，所以你可以在动画过程中移动sx1和sx2，它会将要绘制的图像部分移动到绘画的d点表面。

如果你不知道如何真正做自定义绘画，我建议你跑到Performing Custom Painting

这是完整的示例

（注意我用作背景的图片是 2000x350）

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;

public class MovingBackgroundDemo {

    public MovingBackgroundDemo() {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new AnimatingPanel());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    private class AnimatingPanel extends JPanel {
        private static final int DIM_W = 350;
        private static final int DIM_H = 350;
        private static final int INCREMENT = 10;

        private BufferedImage backgroundImage;
        private Image runnerImage;

        private int dx1, dy1, dx2, dy2;
        private int srcx1, srcy1, srcx2, srcy2;
        private int IMAGE_WIDTH;

        public AnimatingPanel() {
            initImages();
            initImagePoints();
            Timer timer = new Timer(40, new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    moveBackground();
                    repaint();
                }
            });
            timer.start();

            FlowLayout layout = (FlowLayout)getLayout();
            layout.setHgap(0);
            layout.setVgap(0);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.setColor(Color.WHITE);
            g.fillRect(0, 0, getWidth(), getHeight());
            g.drawImage(backgroundImage, dx1, dy1, dx2, dy2, srcx1, srcy1,
                    srcx2, srcy2, this);
            g.drawImage(runnerImage, 0, 0, getWidth(), getHeight(), this);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(350, 350);
        }

        private void initImagePoints() {
            dx1 = 0;
            dy1 = 0;
            dx2 = DIM_W;
            dy2 = DIM_H;
            srcx1 = 0;
            srcy1 = 0;
            srcx2 = DIM_W;
            srcy2 = DIM_H;
        }

        private void initImages() {
            try {
                runnerImage = new ImageIcon(getClass().getResource("runner.gif")).getImage();
                backgroundImage = ImageIO.read(getClass().getResource(
                        "background.png"));
                IMAGE_WIDTH = backgroundImage.getWidth();
                System.out.println(IMAGE_WIDTH);
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }

        private void moveBackground() {
            if (srcx1 > IMAGE_WIDTH) {
                srcx1 = 0 - DIM_W;
                srcx2 = 0;
            } else {
                srcx1 += INCREMENT;
                srcx2 += INCREMENT;
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new MovingBackgroundDemo();
            }
        });
    }
}