这个监听器怎么没效果？？

Question

import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class App_0622 extends JFrame
{ /**
 * @param args
 */private JLabel lbl;
 Container c=getContentPane();

 public App_0622()
 {
 super("Image");
 c.setLayout(new FlowLayout());
 lbl=new JLabel(new ImageIcon("2.png"));
 c.add(lbl);
 //setSize(460,650);
 c.addKeyListener(new hand());
 setVisible(true);  }
class hand extends KeyAdapter
 {
 public void keypressed(KeyEvent e)
 {
 if(e.getKeyChar()=='r')
 {
 for(int i=0;i<30;i++)
 {
 try
 {
 Thread.sleep(70);
 c.setSize(16*i,22*i);
 }
 catch(InterruptedException q)
         {
          
         }
 }
 }
 if(e.getKeyChar()=='p')
 {
 for( int i=29;i>0;i--)
 {
 try
 {
 Thread.sleep(70);
 c.setSize(16*i,22*i);
 }
 catch(InterruptedException q)
         {
          
         }
 }
 }
 }
 }
public static void main(String[] args) 
{
// TODO Auto-generated method stub
App_0622 App=new App_0622();
}}想实现程序运行后，按下r 窗口变大，按下p 变小，但是却没反应，哪里出错呢？？

Answer 1

import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class App_0622 extends JFrame
{    /**
     * @param args
     */private JLabel lbl;
     Container c=getContentPane();
    
     public App_0622()
     {
         super("Image");
         c.setLayout(new FlowLayout());
         lbl=new JLabel(new ImageIcon("2.png"));
         c.add(lbl);
         //setSize(460,650);
         addKeyListener(new hand()); //这里应该是给JFrame加监听
         setVisible(true);     }
    class hand extends KeyAdapter
     {
         public void keyPressed(KeyEvent e) //这里写错了，你写成keypressed了
         {
             if(e.getKeyChar()=='r')
             {
              System.out.println("r");
                 for(int i=0;i<30;i++)
                 {
                     try
                     {
                     Thread.sleep(70);
                     setSize(16*i,22*i); //这里应该是设置JFrame的大小
                     }
                     catch(InterruptedException q)
                     {
                      
                     }
                 }
             }
             if(e.getKeyChar()=='p')
             {
              System.out.println("p");
                 for( int i=29;i>0;i--)
                 {
                     try
                     {
                     Thread.sleep(70);
                     setSize(16*i,22*i); //这里应该是设置JFrame的大小
                     }
                     catch(InterruptedException q)
                     {
                      
                     }
                 }
             }
         }
     }
    public static void main(String[] args) 
    {
        // TODO Auto-generated method stub
        App_0622 App=new App_0622();
    }}

Answer 2

正解，lz如果按你那种写法
应该是
public App_0622()
     {
         super("Image");
         c.setLayout(new FlowLayout());
         lbl=new JLabel(new ImageIcon("2.png"));
         c.add(lbl);
         //setSize(460,650);
         c.addKeyListener(new hand());
         add(c);   //不要忘了在Frame里添加c,否则当然看不到你要的效果
         setVisible(true);     }