不用写出完整代码，用java实现：重点实现控制主角坦克运动，使用键盘监听器来处理玩家输入。根据玩家按键来改变坦克的位置和方向。已有坦克四个方向的图片，分别命名为left、right、down、up，存储在tank文件夹中。

好的，以下是一个简单的示例代码，演示了如何使用键盘监听器控制主角坦克的运动方向：

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

public class TankGame extends JPanel implements KeyListener {
    private static final int WINDOW_WIDTH = 800;
    private static final int WINDOW_HEIGHT = 600;
    private static final int TANK_WIDTH = 50;
    private static final int TANK_HEIGHT = 50;
    
    private Image tankLeft;
    private Image tankRight;
    private Image tankUp;
    private Image tankDown;
    private int playerXPosition;
    private int playerYPosition;
    private Direction playerDirection;

    public TankGame() {
        loadImages();
        initPlayerTank();
        setPreferredSize(new Dimension(WINDOW_WIDTH, WINDOW_HEIGHT));
        setFocusable(true);
        addKeyListener(this);
    }

    private void loadImages() {
        // 加载坦克图片
        tankLeft = new ImageIcon("tank/left.png").getImage();
        tankRight = new ImageIcon("tank/right.png").getImage();
        tankUp = new ImageIcon("tank/up.png").getImage();
        tankDown = new ImageIcon("tank/down.png").getImage();
    }

    private void initPlayerTank() {
        // 初始化主角坦克的位置和方向
        playerXPosition = WINDOW_WIDTH / 2 - TANK_WIDTH / 2;
        playerYPosition = WINDOW_HEIGHT / 2 - TANK_HEIGHT / 2;
        playerDirection = Direction.UP;
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);

        // 绘制主角坦克
        Image playerTankImage = getPlayerTankImage();
        g.drawImage(playerTankImage, playerXPosition, playerYPosition, TANK_WIDTH, TANK_HEIGHT, this);
    }

    private Image getPlayerTankImage() {
        // 根据主角坦克的方向返回对应的图片
        switch (playerDirection) {
            case LEFT:
                return tankLeft;
            case RIGHT:
                return tankRight;
            case UP:
                return tankUp;
            case DOWN:
                return tankDown;
            default:
                return null;
        }
    }

    @Override
    public void keyPressed(KeyEvent e) {
        int keyCode = e.getKeyCode();

        // 根据按键改变主角坦克的位置和方向
        switch (keyCode) {
            case KeyEvent.VK_LEFT:
                playerDirection = Direction.LEFT;
                playerXPosition -= 10;
                break;
            case KeyEvent.VK_RIGHT:
                playerDirection = Direction.RIGHT;
                playerXPosition += 10;
                break;
            case KeyEvent.VK_UP:
                playerDirection = Direction.UP;
                playerYPosition -= 10;
                break;
            case KeyEvent.VK_DOWN:
                playerDirection = Direction.DOWN;
                playerYPosition += 10;
                break;
        }

        repaint();
    }

    @Override
    public void keyTyped(KeyEvent e) {
    }

    @Override
    public void keyReleased(KeyEvent e) {
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            JFrame frame = new JFrame("Tank Game");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.getContentPane().add(new TankGame());
            frame.pack();
            frame.setLocationRelativeTo(null);
            frame.setVisible(true);
        });
    }

    private enum Direction {
        LEFT, RIGHT, UP, DOWN
    }
}

请注意，这只是一个简单的示例，实际的游戏实现可能更加复杂。你可以根据自己的需求进行修改和扩展。在这个示例中，我们使用了`KeyListener`来监听键盘事件，并根据按键改变主角坦克的位置和方向。重要的是要确保面板能够获取焦点，并且添加了键盘监听器。