因此，我开始学习Java，并尝试使用java.awt.graphics创建一个基本的Pong游戏。 完成后，我看到游戏无法播放时闪烁很多。 这是我的主要班级，名为“ pong”（真是个创意名称）。
package pong;
import java.applet.Applet;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class pong extends Applet implements Runnable,KeyListener {
public static void main(String[] args){}
public final int W=700,L=500;
p1 player1;
p1 player2;
ball b;
Thread thread;
public void init() {
resize(W,L);
this.addKeyListener(this);
player2 = new p1(1);
b = new ball();
thread= new Thread(this);
player1 = new p1(2);
thread.start();
}
public void paint(Graphics g){
g.setColor(Color.BLACK);
g.fillRect(0,0,W,L);
if(!(b.getX()<-10 || b.getX()>690)){
player1.draw(g);
b.draw(g);
player2.draw(g);
}else if(b.getX()<-10){
g.setColor(Color.WHITE);
g.drawString("Right Player Won!",350,250);
}else{
g.setColor(Color.WHITE);
g.drawString("Left Player Won!",350,250);
}
}
@Override
public void update(Graphics g){
paint(g);
}
public void run() {
for(;;){
player1.move();
player2.move();
b.move();
colitionchecker(1);
repaint();
try {
Thread.sleep(17);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public void keyTyped(KeyEvent e) {
}
public void keyPressed(KeyEvent e) {
if(e.getKeyCode()==KeyEvent.VK_UP)
player1.setUp(true);
else if (e.getKeyCode()==KeyEvent.VK_DOWN)
player1.setDown(true);
else if(e.getKeyCode()==KeyEvent.VK_W)
player2.setUp(true);
else if(e.getKeyCode()==KeyEvent.VK_S)
player2.setDown(true);
}
public void keyReleased(KeyEvent e) {
if(e.getKeyCode()==KeyEvent.VK_UP)
player1.setUp(false);
else if (e.getKeyCode()==KeyEvent.VK_DOWN)
player1.setDown(false);
else if(e.getKeyCode()==KeyEvent.VK_W)
player2.setUp(false);
else if(e.getKeyCode()==KeyEvent.VK_S)
player2.setDown(false);
}
public void colitionchecker(int num){
if(num == 1){
if(b.getX()<50 && b.getX()>20 && b.getY()>player2.getY() &&
b.getY()>=player2.getY()-80){
b.xv=-b.xv;
}
else{
if(b.getX()<700 && b.getX()>660 && b.getY()>=player1.getY() && b.getY()<=player1.getY()+80){
b.xv=-b.xv;
}
}
}
}
}
package pong;
import java.awt.*;
public class p1 implements paddle{
final double GRAVITY = 0.94;
double y=210,yv;
boolean up,down;
int player,x;
public p1(int player){
up=false; down=false;
if(player==1)
x=20;
else
x=660;
}
@Override
public void draw(Graphics g) {
g.setColor(Color.WHITE);
g.fillRect(x, (int)y,20,80);
}
public void move() {
if (up){
yv -= 2;
}else if (down){
yv += 2;
}else if (!down && !up){
yv *= GRAVITY;
}
if(yv>=15)
yv=5;
else if(yv<=-5)
yv=-5;
y += yv;
if(y<=0)
y=0;
else if(y>=420)
y=420;
}
public void setUp(boolean up) {
this.up = up;
}
public void setDown(boolean down) {
this.down = down;
}
public int getY() {
return (int)y;
}
}
package pong;
import java.awt.*;
public class ball {
double xv, yv, x, y;
public ball(){
x = 350;
y = 250;
xv = 2;
yv = 1;
}
public int getY() {
return (int)y;
}
public int getX() {
return (int)x;
}
public void move(){
x+=xv;
y+=yv;
if(y<10)
yv=-yv;
if(y>490)
yv=-yv;
}
public void draw(Graphics g){
g.setColor(Color.WHITE);
g.fillOval((int)x-10,(int)y-10,20,20);
}
}
package pong;
import java.awt.*;
public interface paddle {
public void draw(Graphics g);
public int getY();
public void move();
}
我真的迷路了，我们将不胜感激。 谢谢。
答案 0 :(得分：2)
所以我开始学习Java
因此，您的第一课是Applets已经死了-最好花一些时间在其他地方使用基于Swing或JavaFX Windows的UI。
Applet不是双重缓冲的，因此，如果正确使用，则Swing和JavaFX都将闪烁。
由于大多数GUI框架都不是线程安全的，因此我也劝阻您不要使用Thread
我建议看看：
作为基本出发点
因为我可以很快做到...
KeyListener是一个糟糕的选择，它会困扰您，最好使用旨在克服其局限性的Key Bindings API
您将需要阅读的内容...
作为总体基本示例
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private DefaultPaddle player1;
private DefaultPaddle player2;
private Ball b;
public TestPane() {
setBackground(Color.BLACK);
player1 = new DefaultPaddle(1);
player2 = new DefaultPaddle(2);
b = new Ball();
addKeyBinding(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0, false), "Player1.up.pressed", new UpAction(player1, true));
addKeyBinding(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0, true), "Player1.up.released", new UpAction(player1, false));
addKeyBinding(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0, false), "Player1.down.pressed", new DownAction(player1, true));
addKeyBinding(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0, true), "Player1.down.released", new DownAction(player1, false));
addKeyBinding(KeyStroke.getKeyStroke(KeyEvent.VK_W, 0, false), "Player2.up.pressed", new UpAction(player2, true));
addKeyBinding(KeyStroke.getKeyStroke(KeyEvent.VK_W, 0, true), "Player2.up.released", new UpAction(player2, false));
addKeyBinding(KeyStroke.getKeyStroke(KeyEvent.VK_S, 0, false), "Player2.down.pressed", new DownAction(player2, true));
addKeyBinding(KeyStroke.getKeyStroke(KeyEvent.VK_S, 0, true), "Player2.down.released", new DownAction(player2, false));
Timer timer = new Timer(5, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
player1.move();
player2.move();
b.move();
// colitionchecker(1);
repaint();
}
});
timer.start();
}
protected void addKeyBinding(KeyStroke ks, String name, Action action) {
InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW);
ActionMap am = getActionMap();
im.put(ks, name);
am.put(name, action);
}
public void colitionchecker(int num) {
if (num == 1) {
if (b.getX() < 50 && b.getX() > 20 && b.getY() > player2.getY()
&& b.getY() >= player2.getY() - 80) {
b.xv = -b.xv;
} else {
if (b.getX() < 700 && b.getX() > 660 && b.getY() >= player1.getY() && b.getY() <= player1.getY() + 80) {
b.xv = -b.xv;
}
}
}
}
@Override
public Dimension getPreferredSize() {
return new Dimension(700, 500);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.BLACK);
// if (!(b.getX() < -10 || b.getX() > 690)) {
player1.draw(g);
b.draw(g);
player2.draw(g);
// } else if (b.getX() < -10) {
// g.setColor(Color.WHITE);
// g.drawString("Right Player Won!", 350, 250);
// } else {
// g.setColor(Color.WHITE);
// g.drawString("Left Player Won!", 350, 250);
// }
g2d.dispose();
}
}
public class UpAction extends AbstractAction {
private DefaultPaddle paddle;
private boolean pressed;
public UpAction(DefaultPaddle paddle, boolean pressed) {
this.paddle = paddle;
this.pressed = pressed;
}
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("Up " + pressed);
paddle.setUp(pressed);
}
}
public class DownAction extends AbstractAction {
private DefaultPaddle paddle;
private boolean pressed;
public DownAction(DefaultPaddle paddle, boolean pressed) {
this.paddle = paddle;
this.pressed = pressed;
}
@Override
public void actionPerformed(ActionEvent e) {
paddle.setDown(pressed);
}
}
public interface Paddle {
public void draw(Graphics g);
public int getY();
public void move();
}
public class DefaultPaddle implements Paddle {
final double GRAVITY = 0.94;
double y = 210, yv;
boolean up, down;
int player, x;
public DefaultPaddle(int player) {
up = false;
down = false;
if (player == 1) {
x = 20;
} else {
x = 660;
}
}
@Override
public void draw(Graphics g) {
g.setColor(Color.WHITE);
g.fillRect(x, (int) y, 20, 80);
}
public void move() {
if (up) {
yv -= 1;
} else if (down) {
yv += 1;
} else if (!down && !up) {
yv *= GRAVITY;
}
if (yv >= 15) {
yv = 5;
} else if (yv <= -5) {
yv = -5;
}
y += yv;
if (y <= 0) {
y = 0;
} else if (y >= 420) {
y = 420;
}
}
public void setUp(boolean up) {
this.up = up;
}
public void setDown(boolean down) {
this.down = down;
}
public int getY() {
return (int) y;
}
}
public class Ball {
double xv, yv, x, y;
public Ball() {
x = 350;
y = 250;
xv = 2;
yv = 1;
}
public int getY() {
return (int) y;
}
public int getX() {
return (int) x;
}
public void move() {
x += xv;
y += yv;
if (y < 10) {
yv = -yv;
}
if (y > 490) {
yv = -yv;
}
}
public void draw(Graphics g) {
g.setColor(Color.WHITE);
g.fillOval((int) x - 10, (int) y - 10, 20, 20);
}
}
}