如何在 Java 中根据按键移动图像？

如何在 Java 中监听按键时使图像移动

在 Java 中，您可以结合使用 Swing Timer 和 Key在聆听按键时使图像移动的绑定。操作方法如下：

1. 创建 Swing 计时器： Swing 计时器用于定期执行任务。在这种情况下，您可以使用它来更新图像的位置。
2. 定义按键绑定：按键绑定将按键与特定操作相关联。您可以使用键绑定来检测用户何时按下某个键并相应地移动图像。
3. 绘制图像： 重写 JPanel 的 PaintComponent 方法以在其当前位置绘制图像.

示例代码：

以下示例代码演示了如何使用 Swing 计时器和按键绑定在监听按键时使图像移动：

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ImageMoveOnKeyPress extends JPanel implements ActionListener {

    private Image image; // The image to be moved
    private int x, y; // The current position of the image

    private Timer timer; // The Swing Timer to update the image position
    private KeyBindings keyBindings; // The Key Bindings to detect keypresses

    public ImageMoveOnKeyPress() {
        // Load the image
        image = Toolkit.getDefaultToolkit().getImage("image_path");

        // Set the initial position of the image
        x = 50;
        y = 50;

        // Create a Swing Timer to update the image position
        timer = new Timer(10, this); // 10 milliseconds delay
        timer.start();

        // Create Key Bindings to detect keypresses
        keyBindings = new KeyBindings();
        getInputMap().put(KeyEvent.VK_LEFT, "left");
        getInputMap().put(KeyEvent.VK_RIGHT, "right");
        getInputMap().put(KeyEvent.VK_UP, "up");
        getInputMap().put(KeyEvent.VK_DOWN, "down");
        getActionMap().put("left", keyBindings.new MoveLeftAction());
        getActionMap().put("right", keyBindings.new MoveRightAction());
        getActionMap().put("up", keyBindings.new MoveUpAction());
        getActionMap().put("down", keyBindings.new MoveDownAction());
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawImage(image, x, y, null);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        // Update the image position based on keypress
        if (keyBindings.isLeftPressed()) {
            x -= 1;
        } else if (keyBindings.isRightPressed()) {
            x += 1;
        } else if (keyBindings.isUpPressed()) {
            y -= 1;
        } else if (keyBindings.isDownPressed()) {
            y += 1;
        }

        // Repaint the panel to display the moved image
        repaint();
    }

    private class KeyBindings {
        private boolean leftPressed, rightPressed, upPressed, downPressed;

        public boolean isLeftPressed() {
            return leftPressed;
        }

        public void setLeftPressed(boolean leftPressed) {
            this.leftPressed = leftPressed;
        }

        public boolean isRightPressed() {
            return rightPressed;
        }

        public void setRightPressed(boolean rightPressed) {
            this.rightPressed = rightPressed;
        }

        public boolean isUpPressed() {
            return upPressed;
        }

        public void setUpPressed(boolean upPressed) {
            this.upPressed = upPressed;
        }

        public boolean isDownPressed() {
            return downPressed;
        }

        public void setDownPressed(boolean downPressed) {
            this.downPressed = downPressed;
        }

        private class MoveLeftAction extends AbstractAction {
            @Override
            public void actionPerformed(ActionEvent e) {
                leftPressed = true;
            }
        }

        private class MoveRightAction extends AbstractAction {
            @Override
            public void actionPerformed(ActionEvent e) {
                rightPressed = true;
            }
        }

        private class MoveUpAction extends AbstractAction {
            @Override
            public void actionPerformed(ActionEvent e) {
                upPressed = true;
            }
        }

        private class MoveDownAction extends AbstractAction {
            @Override
            public void actionPerformed(ActionEvent e) {
                downPressed = true;
            }
        }
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame();

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