使用KeyListener的Pong控件 [英] Pong Controls With KeyListener
本文介绍了使用KeyListener的Pong控件的处理方法，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
我的乒乓球游戏开始工作时遇到了麻烦，这个项目只是从使球具有物理性开始的，然后我决定做更多的工作
I have ran into a bit of trouble getting my pong game to work, this project started simply with making a ball have physics but then i decided to do some more work
我让球来回弹跳，除了键W和S之外，其他所有键都不控制玩家1，而向上和向下箭头键则不控制玩家2
I have that ball bounce back and forth and all but the keys W and S wont control player one and the up and down arrow keys dont control player 2
public void keyPressed(KeyEvent e){
if(e.getKeyCode() == e.VK_UP){
p2Y -= 3;
System.out.println("UP");
}
if(e.getKeyCode() == e.VK_DOWN){
p2Y += 3;
System.out.println("Down");
}
if(e.getKeyCode() == e.VK_W){
p1Y -= 3;
System.out.println("Up");
}
if(e.getKeyCode() == e.VK_S){
p1Y += 3;
System.out.println("down");
}
repaint();
}
它甚至不会显示系统打印消息
It wont even show the system print messages
我不知道这只是问题的代码的这一部分还是其他地方
I dont know if its just this part of the code that is the problem or if its somewhere else
如果在其他位置，则是此文件其余部分的链接 http://pastebin.com/TJbLBxL7
If it is somewhere else here is the link to the rest of this file http://pastebin.com/TJbLBxL7
整个代码:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
public class Pong extends JPanel
{
Circle circle1;
javax.swing.Timer timer;
ArrayList<Point> points = new ArrayList<Point>();
int p1X=10, p1Y=320;
int p2X=760, p2Y = 320;
int y, y1;
int p1Score, p2Score;
boolean playing = true;
public Pong(Color backcolor, int Width, int Height)
{
setBackground(backcolor);
setPreferredSize(new Dimension(Width, Height));
//first circle
circle1 = new Circle(Width / 2, 360, 15, Color.white);
circle1.setVelocity(4);
circle1.setDirection(180);
timer = new javax.swing.Timer(5, new MoveListener());
addKeyListener(new KeyWatcher());
timer.start();
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
//first circle
circle1.draw(g);
circle1.fill(g);
// Draw Players
g.setColor(Color.red);
g.fillRect(p1X, p1Y, 10, 75);
g.setColor(Color.blue);
g.fillRect(p2X, p2Y, 10, 75);
//Draw Scores
g.setColor(Color.white);
g.drawString("Player 1's Score: " + p1Score, 10, 10);
g.drawString("Player 2's Score: " + p2Score, getWidth() - 120, 10);
repaint();
if(!playing)
{
g.setColor(Color.red);
g.drawString("GAMEOVER!!!", (getWidth() / 2) - 15, 10);
}
else
{
}
}
private class MoveListener extends MouseAdapter implements ActionListener
{
public void actionPerformed(ActionEvent arg0)
{
int x1 = circle1.getX();
int y1 = circle1.getY();
int width = getWidth();
int height = getHeight();
int radius1 = circle1.getRadius();
//first circle
if(x1 - radius1 <= 0)
{
p2Score++;
circle1.setX(getWidth()/2);
circle1.setY(getHeight()/2);
}
if(x1 + radius1 >= width)
{
p1Score++;
circle1.setX(getWidth()/2);
circle1.setY(getHeight()/2);
}
if(y1 - radius1 <= 0 || y1 + radius1 >= height )
{
circle1.turnY();
}
if((x1 - radius1 == p1X) || (x1 + radius1 == p2X))
{
circle1.turnX();
}
circle1.move();
repaint();
}
public void GameOver()
{
playing = false;
}
}
private class KeyWatcher implements KeyListener
{
@Override
public void keyPressed(KeyEvent e){
if(e.getKeyCode() == e.VK_UP){
p2Y -= 3;
System.out.println("UP");
}
if(e.getKeyCode() == e.VK_DOWN){
p2Y += 3;
System.out.println("Down");
}
if(e.getKeyCode() == e.VK_W){
p1Y -= 3;
System.out.println("Up");
}
if(e.getKeyCode() == e.VK_S){
p1Y += 3;
System.out.println("down");
}
repaint();
}
@Override
public void keyReleased(KeyEvent e){
//if(e.getKeyCode() == e.VK_UP){
// y1 = p2Y;
// repaint();
// }
// if(e.getKeyCode() == e.VK_DOWN){
// y1 = p2Y;
// repaint();
// }
//if(e.getKeyCode() == e.VK_W){
// y = p1Y;
// repaint();
// }
// if(e.getKeyCode() == e.VK_S){
// y = p1Y;
// repaint();
// }
}
@Override
public void keyTyped(KeyEvent arg0) {
// TODO Auto-generated method stub
}
}
}
我的新密码 这个问题是，一次只能控制一个玩家
My New Code The problem with this one is that only one player can be controlled at a time
我也做出了愚蠢的尝试，使其成为2 MyKeyAction来解决它，但是它根本没有改变
It also has my foolish attempt to fix it by making 2 MyKeyAction but it didnt change it at all
package Bouncy;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
public class Pong extends JPanel
{
Circle circle1;
javax.swing.Timer timer;
ArrayList<Point> points = new ArrayList<Point>();
int p1X=10, p1Y=320;
int p2X=760, p2Y = 320;
int y, y1;
int p1Score, p2Score;
boolean playing = true;
public Pong(Color backcolor, int Width, int Height)
{
setBackground(backcolor);
setPreferredSize(new Dimension(Width, Height));
//first circle
circle1 = new Circle(Width / 2, 360, 15, Color.white);
circle1.setVelocity(4);
circle1.setDirection(180);
timer = new javax.swing.Timer(5, new MoveListener());
setupKeyBinding();
setupKeyBinding2();
timer.start();
}
private void setupKeyBinding() {
int condition = JComponent.WHEN_IN_FOCUSED_WINDOW;
InputMap inMap = getInputMap(condition);
ActionMap actMap = getActionMap();
// this uses an enum of Direction that holds ints for the arrow keys
for (DirectionP1 direction : DirectionP1.values()) {
int key = direction.getKey();
String name = direction.name();
// add the key bindings for arrow key and shift-arrow key
inMap.put(KeyStroke.getKeyStroke(key, 0), name);
inMap.put(KeyStroke.getKeyStroke(key, InputEvent.SHIFT_DOWN_MASK), name);
actMap.put(name, new MyKeyAction(direction));
}
}
private void setupKeyBinding2() {
int condition = JComponent.WHEN_IN_FOCUSED_WINDOW;
InputMap inMap = getInputMap(condition);
ActionMap actMap = getActionMap();
// this uses an enum of Direction that holds ints for the arrow keys
for (DirectionP2 direction : DirectionP2.values()) {
int key = direction.getKey();
String name = direction.name();
// add the key bindings for arrow key and shift-arrow key
inMap.put(KeyStroke.getKeyStroke(key, 0), name);
inMap.put(KeyStroke.getKeyStroke(key, InputEvent.SHIFT_DOWN_MASK), name);
actMap.put(name, new MyKeyAction2(direction));
}
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
//first circle
circle1.draw(g);
circle1.fill(g);
// Draw Players
g.setColor(Color.red);
g.fillRect(p1X, p1Y, 10, 75);
g.setColor(Color.blue);
g.fillRect(p2X, p2Y, 10, 75);
//Draw Scores
g.setColor(Color.white);
g.drawString("Player 1's Score: " + p1Score, 10, 10);
g.drawString("Player 2's Score: " + p2Score, getWidth() - 120, 10);
repaint();
if(!playing)
{
g.setColor(Color.red);
g.drawString("GAMEOVER!!!", (getWidth() / 2) - 15, 10);
}
else
{
}
}
private class MoveListener extends MouseAdapter implements ActionListener
{
public void actionPerformed(ActionEvent arg0)
{
int x1 = circle1.getX();
int y1 = circle1.getY();
int width = getWidth();
int height = getHeight();
int radius1 = circle1.getRadius();
//first circle
if(x1 - radius1 <= 0)
{
p2Score++;
circle1.setX(getWidth()/2);
circle1.setY(getHeight()/2);
}
if(x1 + radius1 >= width)
{
p1Score++;
circle1.setX(getWidth()/2);
circle1.setY(getHeight()/2);
}
if(y1 - radius1 <= 0 || y1 + radius1 >= height )
{
circle1.turnY();
}
if((x1 - radius1 <= p1X) || (x1 + radius1 >= p2X))
{
circle1.turnX();
}
circle1.move();
repaint();
}
public void GameOver()
{
playing = false;
}
}
enum DirectionP1 {
W(KeyEvent.VK_W), S(KeyEvent.VK_S);
private int key;
private DirectionP1(int key) {
this.key = key;
}
public int getKey() {
return key;
}
}
enum DirectionP2 {
UP(KeyEvent.VK_UP), DOWN(KeyEvent.VK_DOWN);
private int key;
private DirectionP2(int key) {
this.key = key;
}
public int getKey() {
return key;
}
}
class MyKeyAction extends AbstractAction {
private DirectionP1 direction;
public MyKeyAction(DirectionP1 direction) {
this.direction = direction;
}
@Override
public void actionPerformed(ActionEvent e) {
switch (direction) {
case W:
p1Y -= 6;
break;
case S:
p1Y += 6;
break;
default:
break;
}
}
}
class MyKeyAction2 extends AbstractAction {
private DirectionP2 direction2;
public MyKeyAction2(DirectionP2 direction2) {
this.direction2 = direction2;
}
@Override
public void actionPerformed(ActionEvent e) {
switch (direction2) {
case UP:
p2Y -= 6;
break;
case DOWN:
p2Y += 6;
break;
default:
break;
}
}
}
}
推荐答案
您遇到了焦点问题.您正在向JPanel添加KeyListener:但是JPanel永远不会具有焦点，因此KeyListener将无法工作:
You have a focus issue. You're adding a KeyListener to a JPanel: but the JPanel never has focus and so the KeyListener won't work:
public class Pong extends JPanel
{
//...
public Pong(Color backcolor, int Width, int Height)
{
// ...
timer = new javax.swing.Timer(5, new MoveListener());
addKeyListener(new KeyWatcher());
但是JPanel永远不会获得焦点，并且KeyListeners仅在正在侦听的组件具有焦点的情况下起作用.
But the JPanel never gets the focus, and KeyListeners only work if the component being listened to has the focus.
一个更好的解决方案不是在KeyListeners上中继，而是使用Swing Timer和Key Bindings.有关此示例，请参见此链接.
A a better solution is not to relay on KeyListeners but instead to use a Swing Timer and Key Bindings. Please see this link for an example of this.
编辑:或者甚至更好的链接- Java KeyListener未注册箭头键.
Edit: Or an even better link -- Java KeyListener Not Registering Arrow Keys.
编辑2
也许更好的解决方案是使用按键绑定，但是使用它们来在按键或释放按键时设置类的字段，然后使用Swing计时器作为游戏循环来轮询这些字段.
Edit 2
Perhaps a better solution is to use Key Bindings but use them to set fields of the class on key press or key release, and then use a Swing Timer as the game loop to poll those fields.
例如，这不会显示动画(由您决定)，但是表明此技术将允许对同时按下的键做出响应:
For example, this doesn't show the animation (that's up to you) but shows that this technique will allow response to simultaneous key presses:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.util.EnumMap;
import javax.swing.*;
public class NewArrowTest extends JPanel {
private static final String PRESSED = "pressed";
private static final String RELEASED = "released";
private static final int TIMER_DELAY = 20;
private EnumMap<Key, Boolean> keyMap = new EnumMap<NewArrowTest.Key, Boolean>(Key.class);
public NewArrowTest() {
keyMap.put(Key.W, false);
keyMap.put(Key.S, false);
keyMap.put(Key.UP, false);
keyMap.put(Key.DOWN, false);
// set up key binding
ActionMap actionMap = getActionMap();
int condition = JComponent.WHEN_IN_FOCUSED_WINDOW;
InputMap inputMap = getInputMap(condition);
for (Key key : Key.values()) {
KeyStroke pressedKeyStroke = KeyStroke.getKeyStroke(key.getKeyCode(), 0, false);
KeyStroke releasedKeyStroke = KeyStroke.getKeyStroke(key.getKeyCode(), 0, true);
inputMap.put(pressedKeyStroke, key.getText() + PRESSED);
inputMap.put(releasedKeyStroke, key.getText() + RELEASED);
actionMap.put(key.getText() + PRESSED, new MyArrowBinding(key, false));
actionMap.put(key.getText() + RELEASED, new MyArrowBinding(key, true));
}
// start polling timer or game loop
new Timer(TIMER_DELAY, new TimerListener()).start();
}
private static void createAndShowGui() {
NewArrowTest mainPanel = new NewArrowTest();
JFrame frame = new JFrame("NewArrowTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
private class TimerListener implements ActionListener {
public void actionPerformed(java.awt.event.ActionEvent e) {
for (Key key : keyMap.keySet()) {
System.out.printf("%6s %b%n", key, keyMap.get(key));
// here we'd move things based on which key is true
}
System.out.println();
};
}
private class MyArrowBinding extends AbstractAction {
private Key key;
private boolean released;
public MyArrowBinding(Key key, boolean released) {
this.key = key;
this.released = released;
}
@Override
public void actionPerformed(ActionEvent aEvt) {
keyMap.put(key, !released);
}
}
enum Direction {
UP("Up"), DOWN("Down"), NEUTRAL("Neutral");
private String text;
private Direction(String text) {
this.text = text;
}
public String getText() {
return text;
}
}
enum Key {
W("W", Direction.UP, KeyEvent.VK_W), S("S", Direction.DOWN, KeyEvent.VK_S),
UP("Up", Direction.UP, KeyEvent.VK_UP), DOWN("Down", Direction.DOWN, KeyEvent.VK_DOWN);
private String text;
private Direction direction;
private int keyCode;
private Key(String text, Direction direction, int keyCode) {
this.text = text;
this.direction = direction;
this.keyCode = keyCode;
}
public String getText() {
return text;
}
public Direction getDirection() {
return direction;
}
public int getKeyCode() {
return keyCode;
}
}
}
这篇关于使用KeyListener的Pong控件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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