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。

 

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Test_16_11 extends JFrame{
    
    public Test_16_11(){
        JP jp1 = new JP();
        add(jp1);        
        jp1.setFocusable(true);//必须给予焦点，否则KeyListener无法工作
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Test_16_11 t1 = new Test_16_11();
        t1.setSize(300,300);
        t1.setTitle("Test_16_11");
        t1.setLocationRelativeTo(null);
        t1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        t1.setVisible(true);
    }
    
    static class JP extends JPanel{
        private String str = "A";
        private int x,y;
        public JP(){
            addKeyListener(new KeyAdapter(){
                public void keyTyped(KeyEvent e){
                    str = e.getKeyChar()+"";
                }            
            });
            addMouseListener(new MouseAdapter(){
                public void mousePressed(MouseEvent e){
                    x = e.getX();
                    y = e.getY();
                    System.out.println("mouse");
                    repaint();
                }
            });
        }
        
        protected void paintComponent(Graphics g){            
            super.paintComponent(g);
            g.drawString(str, x, y);
        }
    }
}

效果图：