Question

我正试图让我的“鱼”随着WASD键移动。当我运行这个程序时，鱼会出现，但是当我按下按键时它不会移动。我看了看，但我找不到问题。请帮忙。

public class RunGame extends JFrame{

    public RunGame(){
        initRunGame();
    }

    private void initRunGame(){

        add(new Board());

        setResizable(false);
        pack();

        setTitle("Game");
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable(){
            @Override
            public void run(){
                RunGame rg=new RunGame();
                rg.setVisible(true);
            }
        });
    }
}

public class Board extends JPanel implements ActionListener{

    private Timer timer;
    private boolean inGame;
    private final int B_WIDTH=500, B_HEIGHT=400;
    private final int DELAY=15;

    private MoveableSprite fish;
    private final int FISH_W=10, FISH_H=5;

    public Board(){initBoard();}

    private void initBoard(){
        addKeyListener(new TAdapter());
        setFocusable(true);
        setBackground(Color.WHITE);
        inGame=true;
        setPreferredSize(new Dimension(B_WIDTH,B_HEIGHT));

        fish=new MoveableSprite(B_WIDTH/2,B_HEIGHT/2,FISH_W,FISH_H,this);

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

    private class TAdapter extends KeyAdapter{

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

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

    @Override
    public void paintComponent(Graphics g){

        super.paintComponent(g);

        if(inGame){
            drawObjects(g);
        }else{
            drawGameOver(g);
        }
    }

    private void drawObjects(Graphics g){

        Graphics2D gd=(Graphics2D)g;
        gd.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);

        if(fish.isVisible()){
            gd.setColor(fish.color);
            gd.fill(fish.getShape());
        }
    }

    private void drawGameOver(Graphics g){

        Graphics2D gd=(Graphics2D)g;
        gd.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);

        String message="GAME OVER";
        Font small=new Font("Helvetica", Font.BOLD, 14);
        FontMetrics fm=getFontMetrics(small);
        gd.setColor(Color.BLACK);
        gd.setFont(small);

        gd.drawString(message, B_WIDTH-fm.stringWidth(message), B_HEIGHT/2);
    }

    @Override
    public void actionPerformed(ActionEvent e){

        inGame();

        updateFish();

        repaint();
    }

    private void inGame(){
        if(!inGame){timer.stop();}
    }

    private void updateFish(){
        if(fish.isVisible()){
            fish.move();
        }
    }
}

public class MoveableSprite extends Sprite{

private int dx, dy;
private Board b;

public MoveableSprite(int x, int y, int w, int h, Board b){
    super(x,y,w,h);
    this.b=b;
    setColor(Color.BLUE);
}

public void move(){
    x+=dx; y+=dy;

    if(x<0){x=0;}
    if(y<0){y=0;}
    if(x>b.getWidth()){x=b.getWidth();}
    if(y>b.getHeight()){y=b.getHeight();}
    updateShape();
}

private void updateShape(){
    shape=new Ellipse2D.Double(getX(),getY(),w,h);
}

public void keyPressed(KeyEvent e){

    int key=e.getKeyCode();

    if(key==KeyEvent.VK_A){dx=-1;}
    if(key==KeyEvent.VK_D){dx=1;}
    if(key==KeyEvent.VK_W){dy=-1;}
    if(key==KeyEvent.VK_S){dy=1;}
}

public void keyReleased(KeyEvent e){

    int key=e.getKeyCode();
      if(key==KeyEvent.VK_A||key==KeyEvent.VK_D){dx=0;}
        if(key==KeyEvent.VK_W||key==KeyEvent.VK_S){dy=0;}
    }
}

    public class Sprite {

    protected int x, y, w, h;
    private boolean isVis;
    protected Shape shape;
    protected Color color;

    public Sprite(int x, int y, int w, int h){
        this.x=x; this.y=y; this.w=w; this.h=h;
        isVis=true; color=Color.BLACK;
        initSprite();
    }

    public void setColor(Color c){
        color=c;
    }

    private void initSprite(){
        shape=new Ellipse2D.Double(x,y,w,h);
        updateDimensions();
    }

    public int getX(){return x;}

    public int getY(){return y;}

    public boolean isVisible(){return isVis;}

    public Rectangle getBounds(){
        return new Rectangle(shape.getBounds());
    }

    public Shape getShape(){
        return shape;
    }

    protected void updateDimensions(){
        Rectangle r=getBounds();
        w=(int) r.getWidth();
        h=(int) r.getHeight();
    }
}

到目前为止，这是所有代码。谢谢你的帮助！

Answer 1

我怀疑它是因为这种复制粘贴错误：

private class TAdapter extends KeyAdapter{
    ...
    @Override
    public void keyPressed(KeyEvent e){
        fish.keyReleased(e);  <-- Whoops - should be keyPressed
    }
}

由于keyReleased()方法将dx或dy设置为零，因此ActionListener永远不会得到非零dx或dy。

当您通过阅读代码尝试查找问题时，可以隐藏这些类型的复制/粘贴拼写错误。使用调试器逐步执行代码可以帮助您找到它们。

为什么我的鱼不动？

1 个答案: