ActionListener不适用于addKeyListener（new TAdapter（））

Question

我正在使用Java Gui制作游戏。 我想让角色在键盘上移动。 所以我训练这个例子，但它没有用。

我在Board.java中创建了子类TAdapter。 但是当我按下键盘时，actionPerformed（ActionEvent e）不起作用。

以下是我的代码。

[MovingSpriteEx.java]

import java.awt.EventQueue;

import javax.swing.JFrame;

public class MovingSpriteEx extends JFrame {
    public static final int SCREEN_WIDTH = 900;
    public static final int SCREEN_HEIGHT = 720;

    public MovingSpriteEx() {

        initUI();
    }

    private void initUI() {

        add(new Board()); // ADD THE PANEL

        setSize(900, 720);
        setResizable(false);

        setTitle("Moving sprite");
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {
        // TODO : WHAT IS IT?
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {

                MovingSpriteEx ex = new MovingSpriteEx();
                ex.setVisible(true);
            }
        });
    }

}

[Board.java]

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.Timer;

import javax.swing.JPanel;

public class Board extends JPanel implements ActionListener {

//  private Timer timer;
    private Craft craft;
    private final int DELAY = 10;

    public Board() {
        initBoard();
    }

    private void initBoard() {

        addKeyListener(new TAdapter());

        setFocusable(true);
        setBackground(Color.BLACK);

        craft = new Craft();
//
//      timer = new Timer(DELAY, this);
//      timer.start();
    }

    @Override
    // TODO what is is?
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        doDrawing(g);
        Toolkit.getDefaultToolkit().sync();
    }

    //In the doDrawing() method, we draw the spacecraft with the drawImage() method.
    //  We get the image and the coordinates from the sprite class.
    private void doDrawing(Graphics g) {
        //TODO : what is it?
        Graphics2D g2d = (Graphics2D) g;
        g2d.drawImage(craft.getImage(), craft.getX(), craft.getY(), this);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("call the move");
        craft.move();
        repaint();  
    }

     private class TAdapter extends KeyAdapter {

            @Override
            public void keyReleased(KeyEvent e) {
                craft.keyReleased(e);
            }

            @Override
            public void keyPressed(KeyEvent e) {
                craft.keyPressed(e);
            }
        }

}

[Craft.java]

import java.awt.Image;
import java.awt.event.KeyEvent;

import javax.swing.ImageIcon;


public class Craft {

    private int dx;
    private int dy;
    private int x;
    private int y;
    private Image image;

    public Craft() {
        initCraft();
    }

    private void initCraft() {
        ImageIcon ii = new ImageIcon(MovingSpriteEx.class.getResource("/images/dino_front.png"));

        image = ii.getImage();
        x = 40;
        y = 60;
    }

    public void move() {
        System.out.println("move");
        x += dx;
        y += dy;
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

    public Image getImage() {
        return image;
    }

    public void keyPressed(KeyEvent e) {
        int key = e.getKeyCode();

        if (key == KeyEvent.VK_LEFT) {
            System.out.println("key pressed");
            dx = -1;
        }

        if (key == KeyEvent.VK_RIGHT) {
            dx = 1;
        }

        if (key == KeyEvent.VK_UP) {
            dy = -1;
        }

        if (key == KeyEvent.VK_DOWN) {
            dy = 1;
        }

    }

    public void keyReleased(KeyEvent e) {
        System.out.println("key released");
        int key = e.getKeyCode();

        if (key == KeyEvent.VK_LEFT) {
            dx = 0;
        }

        if (key == KeyEvent.VK_RIGHT) {
            dx = 0;
        }

        if (key == KeyEvent.VK_UP) {
            dy = 0;
        }

        if (key == KeyEvent.VK_DOWN) {
            dy = 0;
        }
    }
}

问题是什么？