好吧，我这里有两个类，主类和按键监听器类，我用它们将键盘输入传递给主类。
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.image.BufferStrategy;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.JFrame;
public class Game extends Canvas implements Runnable{
private static final long serialVersionUID = 1L;
private final static int WIDTH = 240;
private final static int HEIGHT = WIDTH / 12 * 9;
private final static int SCALE = 2;
private String TITLE = "Game";
private boolean running = false;
private Thread thread;
Random r = new Random();
ArrayList<Point> snakePart = new ArrayList<Point>();
Point head;
KeyHandle keyhandle;
public static void main(String[] args) {
new Game();
}
public Game() {
init();
JFrame frame = new JFrame(TITLE);
Dimension size = new Dimension(WIDTH * SCALE, HEIGHT * SCALE);
setMinimumSize(size);
setMaximumSize(size);
setPreferredSize(size);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(this);
frame.pack();
frame.setVisible(true);
start();
}
public void init() {
head = new Point(0,0);
addKeyListener(new KeyHandle());
}
@Override
public void run() {
final double ticks = 60.0;
long initTime = System.nanoTime();
double ns = 1000000000 / ticks;
double delta = 0;
long timer = System.currentTimeMillis();
double updates = 0;
int frames = 0;
while (running) {
long nowTime = System.nanoTime();
delta += (nowTime - initTime) / ns;
initTime = nowTime;
if (delta >= 1) {
tick();
updates++;
delta--;
}
render();
frames++;
if (System.currentTimeMillis() - timer > 1000) {
timer += 1000;
System.out.println("Ticks: " + updates + " Frames: " + frames);
updates = 0;
frames = 0;
}
}
stop();
}
public void tick() {
}
public void render() {
BufferStrategy bs = getBufferStrategy();
if (bs == null) {
createBufferStrategy(3);
return;
}
Graphics g = bs.getDrawGraphics();
g.setColor(Color.BLACK);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(Color.white);
g.drawRect(head.x, head.y, 10, 10);
bs.show();
g.dispose();
}
private synchronized void start() {
if (running)
return;
running = true;
thread = new Thread(this);
thread.start();
}
private synchronized void stop() {
if (!running)
return;
running = false;
try {
thread.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.exit(1);
}
}
然后我得到了如下所示的 keylistener 类
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class KeyHandle implements KeyListener {
Game game;
@Override
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_UP){
} else if(e.getKeyCode() == KeyEvent.VK_DOWN){
game.head.y += 10;
} else if(e.getKeyCode() == KeyEvent.VK_LEFT){
} else if(e.getKeyCode() == KeyEvent.VK_RIGHT){
} else if(e.getKeyCode() == KeyEvent.VK_ESCAPE){
}
}
@Override
public void keyReleased(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_UP){
} else if(e.getKeyCode() == KeyEvent.VK_DOWN){
} else if(e.getKeyCode() == KeyEvent.VK_LEFT){
} else if(e.getKeyCode() == KeyEvent.VK_RIGHT){
} else if(e.getKeyCode() == KeyEvent.VK_ESCAPE){
}
}
@Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
}
}
现在，当我尝试编辑第二类中看到的“head”y 和 x 值时，问题出现了。
if(e.getKeyCode() == KeyEvent.VK_DOWN){
game.head.y += 10;
我在这里做错了什么，有没有更好的方法来更有效地传递和设置 x 和 y 值。
最佳答案
您的 KeyHandle 类包含对 Game 的引用，但不包含游戏的实例。不要在主方法中创建 new Game() 并将实例放在地板上，而是将该实例分配给 KeyHandle 中包含的引用。
keyhandle.game = new Game();
关于java - 如果我从另一个类设置 x y，则矩形不会移动。，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40531886/