package text1;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class TankGame extends JFrame{

    MyPanel mp;
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        TankGame tg=new TankGame();
    }

    public TankGame()
    {
        mp=new MyPanel();
        this.add(mp);
        this.addKeyListener(mp);
        
        
        this.setSize(400,300);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setVisible(true);


    }
}
class Tank
{
    int x=0,y=0;
    int d=0;
    public int getD() {
        return d;
    }
    public void setD(int d) {
        this.d = 0;
    }
    public int getSpeed() {
        return speed;
    }
    public void setSpeed(int speed) {
        this.speed = speed;
    }
    int speed=1;
    public int getX() {
        return x;
    }
    public void setX(int x) {
        this.x = x;
    }
    public int getY() {
        return y;
    }
    public void setY(int y) {
        this.y = y;
    }
    public Tank(int x,int y)
    {
        this.x=x;
        this.y=y;
    }
   
}
class MyTank extends Tank
{
    public MyTank(int x,int y)
    {
        super(x,y);
    }
    public void moveUp()
    {
        y-=speed;
    }
    public void moveDown()
    {
        y+=speed;
    }
    public void moveLeft()
    {
        x-=speed;
    }
    public void moveRight()
    {
        x+=speed;
    }
}
class MyPanel extends JPanel implements KeyListener
{
    MyTank my=null;
    public void paint(Graphics g)
    {
        my=new MyTank(100,100);
        super.paint(g);
        g.setColor(Color.BLACK);
        g.fillRect(0, 0, 400,300);
        this.drawTank(this.my.getX(),this.my.getY(), g, 0,this.my.getD());
    }
    public void drawTank(int x,int y,Graphics g,int Type,int d)
    {
        switch(Type)
        {
        case 0:
            g.setColor(Color.cyan);
            break;
        case 1:
            g.setColor(Color.green);
            break;
        }
        switch(d)
        {
        case 0:
            g.fill3DRect(x, y, 5,20 ,false);
            g.fill3DRect(x+15, y,5, 20,false);
            g.fill3DRect(x+5, y+4, 10, 12, false);
            g.fillOval(x+5, y+5, 7, 8);
            g.drawLine(x+9, y+9, x+9, y);
            break;
        case 1:
            g.fill3DRect(x, y, 5,20 ,false);
            g.fill3DRect(x+15, y,5, 20,false);
            g.fill3DRect(x+5, y+4, 10, 12, false);
            g.fillOval(x+5, y+5, 7, 8);
            g.drawLine(x+9, y+9, x+9, y);
            break;
        case 2:
            g.fill3DRect(x, y, 5,20 ,false);
            g.fill3DRect(x+15, y,5, 20,false);
            g.fill3DRect(x+5, y+4, 10, 12, false);
            g.fillOval(x+5, y+5, 7, 8);
            g.drawLine(x+9, y+9, x+9, y);
            break;
        case 3:
            g.fill3DRect(x, y, 5,20 ,false);
            g.fill3DRect(x+15, y,5, 20,false);
            g.fill3DRect(x+5, y+4, 10, 12, false);
            g.fillOval(x+5, y+5, 7, 8);
            g.drawLine(x+9, y+9, x+9, y);
            break;
        }
        
    }
    @Override
    public void keyPressed(KeyEvent e) {
        // TODO Auto-generated method stub
         if(e.getKeyCode()==KeyEvent.VK_W)
        {
            this.my.setD(0);
            this.my.moveUp();
        }else if(e.getKeyCode()==KeyEvent.VK_D)
        {
            this.my.setD(1);
            this.my.moveRight();
        }else if(e.getKeyCode()==KeyEvent.VK_S)
        {
            //System.out.println(e.getKeyChar());
            //my.setY(my.getY()+1);
            //System.out.println(my.getY());
            this.my.setD(2);
            this.my.moveDown();
        }else if(e.getKeyCode()==KeyEvent.VK_A)
        {
            this.my.setD(3);
            this.my.moveLeft();
        }
        this.repaint();
    }
    @Override
    public void keyTyped(KeyEvent e) {
        // TODO Auto-generated method stub
        //System.out.println();
        
    }
   
   
    @Override
    public void keyReleased(KeyEvent e) {
        // TODO Auto-generated method stub
   
    }
}

public void paint(Graphics g)
    {
        my=new MyTank(100,100);
        super.paint(g);
        g.setColor(Color.BLACK);
        g.fillRect(0, 0, 400,300);
        this.drawTank(this.my.getX(),this.my.getY(), g, 0,this.my.getD());
    }

没见过调用父类构造方法还能放到下面的

谢谢，问题终于解决啦！