我的“蛇”应用程序。即使没有编译错误，也没有完全显示

Question

我正在尝试创建一个蛇游戏的版本，但它无法正常工作。它现在正在做的是显示一个没有paintComponent部分中任何组件的黑屏。有时它会在一段时间后显示我的“游戏结束”消息，所以有些东西正在工作但蛇和食物没有显示。

我已经尝试了几个小时来查找任何逻辑错误，但一直无法找到。如果有人能指导我做错了什么，我将非常感激。

下面是我设置电路板的代码，下面是我运行程序的主要类。我把整个代码放在你想要在你自己的设备上运行的情况下，但重要的代码片段围绕它们有两颗星。任何建议或意见将不胜感激。

public class Board2 extends JPanel implements ActionListener{

private int bWidth = 500;
private int bHeight = 500;
private int segmentSize = 10;
private int bodyMax = 2500;
private int randomPos = 29;
private int delay = 140;

private int x[] = new int[bodyMax];
private int y[] = new int[bodyMax]; 

private int bodySize, foodX, foodY;

private boolean leftDirection = false;
private boolean rightDirection = true;
private boolean upDirection = false;
private boolean downDirection = false;
private boolean inGame = true;

private Timer timer;
private Image head;
private Image food;
private Image body;

Board2(){
    addKeyListener(new changeDirection());
    setBackground(Color.BLACK);

    setPreferredSize(new Dimension(bWidth, bHeight));
    loadImages();
    init();
}

**private void loadImages(){
    ImageIcon headImage = new ImageIcon("Square-Freemason-Symbols-300x300.png");
    head = headImage.getImage();

    ImageIcon foodImage = new ImageIcon("Square-Freemason-Symbols-300x300.png");
    food = foodImage.getImage();

    ImageIcon bodyImage = new ImageIcon("Flat1.jpg");
    body = bodyImage.getImage();
}**

private void init(){
    bodySize = 3;

    for(int z = 0; z < bodySize; z++){
        x[z] = 50 - z * 10;
        y[z] = 50;
    }

    findFood();

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

@Override
public void paintComponent(Graphics g){
    super.paintComponent(g);
    doDrawing(g);
}

**private void doDrawing(Graphics g){
    if(inGame){
        g.drawImage(food, foodX, foodY, this);

        for(int z = 0; z < bodySize; z++){
            if(z == 0){
                g.drawImage(head, x[z], y[z], this);
            } else {
                g.drawImage(body, x[z], y[z], this);
            }
        }

        Toolkit.getDefaultToolkit().sync();
    } else {
        gameOver(g);
    }
}**

private void gameOver(Graphics g){
    String msg = "Game Over";
    Font small = new Font("Helvetiva", Font.BOLD, 14);
    FontMetrics metr = getFontMetrics(small);

    g.setColor(Color.WHITE);
    g.setFont(small);
    g.drawString(msg, (bWidth - metr.stringWidth(msg)/2), bHeight/2);
}

private void findFood(){
    int r = (int) Math.random() * randomPos;
    foodX = r * segmentSize;

    int s = (int) Math.random() * randomPos;
    foodY = s * segmentSize;
}

private void checkFood(){
    if(x[0] == foodX && y[0] == foodY){
        bodySize += 3;
        findFood();
    }
}

private void checkCollision(){
    for(int z = bodySize; z > 0; z--){
        if(z > 4 && x[0] == x[z] && y[0] == y[z]){
            inGame = false;
        }
    }
    if(x[0] > bWidth){
        inGame = false;
    }
    if(x[0] < 0){
        inGame = false;
    }
    if(y[0] >bHeight){
        inGame = false;
    }
    if(y[0] < 0){
        inGame = false;
    }
}

private void Move(){
    for(int z = bodySize; z > 0; z--){
        x[z] = x[z - 1];
        y[z] = y[z - 1];
    }
    if(leftDirection){
        x[0] -= segmentSize;
    }
    if(rightDirection){
        x[0] += segmentSize;
    }
    if(upDirection){
        y[0] -= segmentSize;
    }
    if(downDirection){
        y[0] += segmentSize;
    }
}

public void actionPerformed(ActionEvent e){
    if(inGame){
        checkFood();
        checkCollision();
        Move();
    }

}

public class changeDirection extends KeyAdapter{
    public void keyPressed(KeyEvent e){
        int key = e.getKeyCode();

        if(key == KeyEvent.VK_LEFT && !rightDirection){
            leftDirection = true;
            upDirection = false;
            downDirection = false;
        }
        if(key == KeyEvent.VK_RIGHT && !leftDirection){
            rightDirection = true;
            upDirection = false;
            downDirection = false;
        }
        if(key == KeyEvent.VK_UP && !downDirection){
            upDirection = true;
            leftDirection = false;
            rightDirection = false;
        }
        if(key == KeyEvent.VK_DOWN && !upDirection){
            downDirection = true;
            leftDirection = false;
            rightDirection = false;
         }
      }
   }
}

这是主要课程：

public class SnakeV2 extends JFrame{

SnakeV2(){

    add(new Board2());
    setResizable(false);
    pack();

    setTitle("SnakeV2");
    setLocationRelativeTo(null);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
}

public static void main(String[] args){
    EventQueue.invokeLater(new Runnable(){

        @Override
        public void run(){
            JFrame ex = new SnakeV2();
            ex.setVisible(true);
        }
    });
}
}