本文介绍了小程序 - KeyListener 不工作的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
当我启动我的小程序时,我没有得到关键侦听器的响应.我该如何解决?下面是代码.
When I start up my applet, I get no response from the key listener. How do I fix this? Below is the code.
import java.applet.Applet;
import java.awt.Graphics;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.util.Timer;
import java.util.TimerTask;
public class Main extends Applet {
private static final long serialVersionUID = 1L;
public String mode = "";
public Graphic gr;
public void init() {
this.setSize(400, 400);
gr = new Graphic();
this.add(gr);
gr.addKeyListener(new MyKeyListener());
TimerTask timerTask = new TimerTask() {
@Override
public void run() {
gr.requestFocus();
gr.repaint();
}
};
new Timer().scheduleAtFixedRate(timerTask, 0, 1000 / 5);
}
public void paint(Graphics g) {
}
private class MyKeyListener extends KeyAdapter {
public MyKeyListener(){
System.out.println("HELLO");
}
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_UP:
gr.direction = Graphic.Direction.up;
gr.move();
break;
case KeyEvent.VK_DOWN:
gr.direction = Graphic.Direction.down;
gr.move();
break;
case KeyEvent.VK_LEFT:
gr.direction = Graphic.Direction.left;
gr.move();
break;
case KeyEvent.VK_RIGHT:
gr.direction = Graphic.Direction.right;
gr.move();
break;
}
}
public void keyReleased(KeyEvent e) {
}
}
}
推荐答案
import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Shape;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class TTest extends Applet{
@Override
public void init() {
// TODO Auto-generated method stub
super.init();
this.setSize(400, 400);
addKeyListener(new KeyListener());
}
class KeyListener extends KeyAdapter{
public KeyListener(){
}
@Override
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
super.keyPressed(e);
switch(e.getKeyCode()){
case KeyEvent.VK_UP:
System.out.println("Pressed up arrow!");
break;
case KeyEvent.VK_DOWN:
System.out.println("Pressed down arrow!");
break;
default:
System.out.println("You pressed: " + e.getKeyCode());
}
}
}
}
您必须将按键事件监听器添加到小程序本身而不是图形对象.但是,我认为除了小程序之外,还可以向对象添加鼠标事件侦听器
You must add key event listener to applet itself not to graphic object. However, I think it is ok to add mouse event listener to objects apart from applet
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