如何在此代码上使用 KeyListener 上下移动？我知道如何使用 KeyListener，但我不知道它把它放在这段代码的什么地方。
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
public class ControlPanel extends JPanel implements Runnable,ActionListener,KeyListener,MouseListener{
private MainPanel main;
private final static int maxWidth = 800, maxHeight = 600; //width & height of JPanel
private boolean running; //keeps track of state of the program
private Thread thread;
private Graphics2D graphics;
private Image image; //used for double buffering
private BufferedImage bgImage;
private String s = "";
Font f = new Font("Times New Roman",Font.PLAIN,50);
Timer t = new Timer(2000,this);
private int typed = 0;
private int x = 50,y = 500;
public ControlPanel(MainPanel main) {
this.setDoubleBuffered(false); //we'll use our own double buffering method
this.setBackground(Color.black);
this.setPreferredSize(new Dimension(maxWidth, maxHeight));
this.setFocusable(true);
this.requestFocus();
this.main = main;
addKeyListener(this);
addMouseListener(this);
t.start();
}
public static void main(String[] args) {
new MainPanel();
}
public void addNotify() {
super.addNotify();
startGame();
}
public void stopGame() {
running = false;
}
//Creates a thread and starts it
public void startGame() {
if (thread == null || !running) {
thread = new Thread(this);
}
thread.start(); //calls run()
}
public void run() {
running = true;
init();
while (running) {
createImage(); //creates image for double buffering
///////////////USE THESE 2 METHODS////////////////////
update(); //use this to change coordinates, update values, etc
draw(); //use this to draw to the screen
//////////////////////////////////////////////////////
drawImage(); //draws on the JPanel
}
System.exit(0);
}
//Use this to create or initialize any variables or objects you have
public void init() {
}
public void initGame(){
}
//Use this to update anything you need to update
public void update() {
}
//Use this to draw anything you need to draw
public void draw() {
graphics.setColor(Color.WHITE);
graphics.fillRect(250, 450, 300,100);
graphics.setColor(Color.WHITE);
graphics.fillRect(250, 320, 300,100);
graphics.setColor(Color.GREEN);
graphics.setFont(f);
graphics.drawString(s, x, y);
typed = 0;
graphics.setFont(f);
graphics.setColor(Color.blue);
graphics.drawString("HANGMAN", 270,75);
graphics.setFont(f);
graphics.setColor(Color.blue);
graphics.drawString("PLAY", 330, 390);
graphics.setFont(f);
graphics.setColor(Color.blue);
graphics.drawString("QUIT", 330, 520);
graphics.setColor(Color.red);
graphics.drawRect(248, 318, 304,104);
}
//creates an image for double buffering
public void createImage() {
if (image == null) {
image = createImage(maxWidth, maxHeight);
if (image == null) {
System.out.println("Cannot create buffer");
return;
}
else
graphics = (Graphics2D)image.getGraphics(); //get graphics object from Image
}
if (bgImage == null) {
graphics.setColor(Color.black);
graphics.fillRect(0, 0, maxWidth, maxHeight);
//System.out.println("No background image");
}
else {
//draws a background image on the Image
graphics.drawImage(bgImage, 0, 0, null);
}
}
//outputs everything to the JPanel
public void drawImage() {
Graphics g;
try {
g = this.getGraphics(); //a new image is created for each frame, this gets the graphics for that image so we can draw on it
if (g != null && image != null) {
g.drawImage(image, 0, 0, null);
g.dispose(); //not associated with swing, so we have to free memory ourselves (not done by the JVM)
}
image = null;
}catch(Exception e) {System.out.println("Graphics objects error");}
}
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
public void keyPressed(KeyEvent e) {
}
public void keyReleased(KeyEvent e) {
}
public void keyTyped(KeyEvent e) {
typed = 1;
s+=Character.toString(e.getKeyChar());
s+=" ";
System.out.println(s);
}
@Override
public void mouseClicked(MouseEvent e) {
System.out.println(e.getPoint());
}
@Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
}
}