1.31

package text;
//键盘移动小球
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;


import javax.swing.*;


public class MyTesta{
public static void main(String[] args) {
JFrame ball = new JFrame();
ball.setSize(1024,765);

MyPanela b = new MyPanela();
ball.add(b);

ball.addKeyListener(b);
b.addKeyListener(b);

ball.setVisible(true);
}
}
class MyPanela extends JPanel implements KeyListener{
int x = 30;
int y = 30;
public void paint(Graphics g) {
super.paint(g);
g.fillOval(x, y, 30, 30);

}
@Override
public void keyPressed(KeyEvent arg0) {
if(arg0.getKeyCode()==38){
y-=5;
}
if(arg0.getKeyCode()==39){
x+=5;
}
if(arg0.getKeyCode()==40){
y+=5;
}
if(arg0.getKeyCode()==37){
x-=5;
}
repaint();
}
@Override
public void keyReleased(KeyEvent arg0) {
// TODO 自动生成的方法存根

}
@Override
public void keyTyped(KeyEvent arg0) {
// TODO 自动生成的方法存根

}
}