Question

e.getKeyCode() == KeyEvent.VK_DOWN然后在按非数字键盘 下 没反应呀？怎么回事。。好急

package gui;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.*;
public class Demo2 extends JFrame{
MyPanel my = null;
public static void main(String[] args) {
// TODO Auto-generated method stub
Demo2 demo2 = new Demo2();
}
public Demo2(){
my = new MyPanel();
this.add(my);
this.addKeyListener(my);//注册监听
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(400, 300);
this.setVisible(true);
}
}
class MyPanel extends JPanel implements KeyListener{
int x = 10;
int y = 10;
public void paintComponent(Graphics g){
super.paintComponent(g);
g.fillOval(x, y, 10, 10);
}
@Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
if(e.getKeyCode() == KeyEvent.VK_DOWN){
System.out.println("ok");
}

}
@Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub

}
@Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub

}
}

Answer 1

对于按下键和释放键事件，getKeyCode 方法返回该事件的 keyCode。对于键入键事件（keyTyped
），getKeyCode 方法总是返回 VK_UNDEFINED（0）。所以条件总是不成立的。

Answer 2

刚刚试验了，好像不行