如何正确添加keylistener

Question

我想把keylistener和“download.jpg”左右移动。我把;但错误说，是必要的。我做错了什么？我需要修复什么？我需要添加任何东西吗？

public class GameScreen extends JPanel implements KeyListener { 

     public BufferedImage bg; 
     public BufferedImage ci; 
     public JLabel lab; 
     int ciXp = 250; 
     int ciYp = 665; 
     int ciWidth = 330; 
     int ciHeight = 745; 

    public GameScreen() 
    { 
     gui(); 

    } 

    public void gui() 
    { 
    try{ 
     bg = ImageIO.read(new File("supermario.jpg")); 
     ci = ImageIO.read(new File("download.png")); 
     } 
     catch(Exception ex){ 
      } 



    } 


    public void paintComponent(Graphics g) 
    { 
     g.drawImage(bg,0,0,null); 
     g.drawImage(ci,ciXp,ciYp,ciWidth,ciHeight,0,0,ci.getWidth(),ci.getHeight(),null); 
    } 

    public void keyPressed(KeyEvent e) { 

    int key = e.getKeyCode(); 

    if (key == KeyEvent.VK_LEFT) { 
     int ciXp-10; 
    } 
    if (key == KeyEvent.VK_RIGHT) { 
     int ciXp+10; 
    } 
} 
} 

Answer 1

添加下面一行在你gui()方法，

addKeyListener(this);