16.11

代码中需要注意的是，由于JPanel需要监听按键，所以需要将JPanel进行聚焦，否则无法监听按键。

 1 import java.awt.*;
 2 import java.awt.event.*;
 3 import javax.swing.*;
 4
 5 public class Test_16_11 extends JFrame{
 6
 7     public Test_16_11(){
 8         JP jp1 = new JP();
 9         add(jp1);
10         jp1.setFocusable(true);//必须给予焦点，否则KeyListener无法工作
11     }
12     public static void main(String[] args) {
13         // TODO Auto-generated method stub
14         Test_16_11 t1 = new Test_16_11();
15         t1.setSize(300,300);
16         t1.setTitle("Test_16_11");
17         t1.setLocationRelativeTo(null);
18         t1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
19         t1.setVisible(true);
20     }
21
22     static class JP extends JPanel{
23         private String str = "A";
24         private int x,y;
25         public JP(){
26             addKeyListener(new KeyAdapter(){
27                 public void keyTyped(KeyEvent e){
28                     str = e.getKeyChar()+"";
29                 }
30             });
31             addMouseListener(new MouseAdapter(){
32                 public void mousePressed(MouseEvent e){
33                     x = e.getX();
34                     y = e.getY();
35                     System.out.println("mouse");
36                     repaint();
37                 }
38             });
39         }
40
41         protected void paintComponent(Graphics g){
42             super.paintComponent(g);
43             g.drawString(str, x, y);
44         }
45     }
46 }

Test_16_11.java

效果图：