我正在java中制作一个非常简单的pong游戏，我正在使用KeyListener进行此操作。我想要它，所以当用户按下键盘上的右键或者左键时，乒乓块就会朝这个方向行进。这是一个足够简单的任务，但我发现当用户按住键时，块会移动一次，短时间停止，然后继续移动，直到用户释放键。我注意到这种情况发生在您试图按住计算机上的字母键时。如果我尝试按住“A”键，计算机会做什么：Java KeyListener口吃
一个[暂停] aaaaaaaaaaaaaaaa
有什么方法来禁用这个口吃，因为它是在的方式获得我的小游戏流畅的游戏。快速解决将深受赞赏。
为例子...
更新为simp例如
在大多数游戏中，您应该对“状态更改”做出反应，而不是实际的关键事件。这意味着，实际上改变的状态可以是可变的事件（想自定义键）
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class SinglePressKeyBinding {
public static void main(String[] args) {
new SinglePressKeyBinding();
}
public SinglePressKeyBinding() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JLabel message;
private boolean spacedOut = false;
public TestPane() {
message = new JLabel("Waiting");
setLayout(new GridBagLayout());
add(message);
InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW);
ActionMap am = getActionMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0, false), "space-pressed");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0, true), "space-released");
am.put("space-pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
if (spacedOut) {
message.setText("I'm ignoring you");
} else {
spacedOut = true;
message.setText("Spaced out");
}
}
});
am.put("space-released", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
spacedOut = false;
message.setText("Back to earth");
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}
我本来约按键绑定一个答案，但一个小的测试后，我发现，他们仍然有同样的口吃问题。
不要依赖OS的重复率。它对于每个平台都可能不同，用户也可以对其进行定制。
而是使用计时器来安排事件。您在keyPressed上启动Timer并在keyReleased上停止Timer。
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.util.Map;
import java.util.HashMap;
import javax.imageio.ImageIO;
import javax.swing.*;
public class KeyboardAnimation implements ActionListener
{
private final static String PRESSED = "pressed ";
private final static String RELEASED = "released ";
private final static Point RELEASED_POINT = new Point(0, 0);
private JComponent component;
private Timer timer;
private Map<String, Point> pressedKeys = new HashMap<String, Point>();
public KeyboardAnimation(JComponent component, int delay)
{
this.component = component;
timer = new Timer(delay, this);
timer.setInitialDelay(0);
}
public void addAction(String keyStroke, int deltaX, int deltaY)
{
// InputMap inputMap = component.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
InputMap inputMap = component.getInputMap();
ActionMap actionMap = component.getActionMap();
String pressedKey = PRESSED + keyStroke;
KeyStroke pressedKeyStroke = KeyStroke.getKeyStroke(pressedKey);
Action pressedAction = new AnimationAction(keyStroke, new Point(deltaX, deltaY));
inputMap.put(pressedKeyStroke, pressedKey);
actionMap.put(pressedKey, pressedAction);
String releasedKey = RELEASED + keyStroke;
KeyStroke releasedKeyStroke = KeyStroke.getKeyStroke(releasedKey);
Action releasedAction = new AnimationAction(keyStroke, RELEASED_POINT);
inputMap.put(releasedKeyStroke, releasedKey);
actionMap.put(releasedKey, releasedAction);
}
private void handleKeyEvent(String keyStroke, Point moveDelta)
{
// Keep track of which keys are pressed
if (RELEASED_POINT == moveDelta)
pressedKeys.remove(keyStroke);
else
pressedKeys.put(keyStroke, moveDelta);
// Start the Timer when the first key is pressed
if (pressedKeys.size() == 1)
{
timer.start();
}
// Stop the Timer when all keys have been released
if (pressedKeys.size() == 0)
{
timer.stop();
}
}
// Invoked when the Timer fires
public void actionPerformed(ActionEvent e)
{
moveComponent();
}
// Move the component to its new location
private void moveComponent()
{
int componentWidth = component.getSize().width;
int componentHeight = component.getSize().height;
Dimension parentSize = component.getParent().getSize();
int parentWidth = parentSize.width;
int parentHeight = parentSize.height;
// Calculate new move
int deltaX = 0;
int deltaY = 0;
for (Point delta : pressedKeys.values())
{
deltaX += delta.x;
deltaY += delta.y;
}
// Determine next X position
int nextX = Math.max(component.getLocation().x + deltaX, 0);
if (nextX + componentWidth > parentWidth)
{
nextX = parentWidth - componentWidth;
}
// Determine next Y position
int nextY = Math.max(component.getLocation().y + deltaY, 0);
if (nextY + componentHeight > parentHeight)
{
nextY = parentHeight - componentHeight;
}
// Move the component
component.setLocation(nextX, nextY);
}
private class AnimationAction extends AbstractAction implements ActionListener
{
private Point moveDelta;
public AnimationAction(String keyStroke, Point moveDelta)
{
super(PRESSED + keyStroke);
putValue(ACTION_COMMAND_KEY, keyStroke);
this.moveDelta = moveDelta;
}
public void actionPerformed(ActionEvent e)
{
handleKeyEvent((String)getValue(ACTION_COMMAND_KEY), moveDelta);
}
}
public static void main(String[] args)
{
JPanel contentPane = new JPanel();
contentPane.setLayout(null);
Icon dukeIcon = null;
try
{
dukeIcon = new ImageIcon("dukewavered.gif");
// dukeIcon = new ImageIcon(ImageIO.read(new URL("http://duke.kenai.com/iconSized/duke4.gif")));
}
catch(Exception e)
{
System.out.println(e);
}
JLabel duke = new JLabel(dukeIcon);
duke.setSize(duke.getPreferredSize());
duke.setLocation(100, 100);
contentPane.add(duke);
KeyboardAnimation navigation = new KeyboardAnimation(duke, 24);
navigation.addAction("LEFT", -3, 0);
navigation.addAction("RIGHT", 3, 0);
navigation.addAction("UP", 0, -3);
navigation.addAction("DOWN", 0, 3);
navigation.addAction("A", -5, 0);
navigation.addAction("S", 5, 0);
navigation.addAction("Z", 0, -5);
navigation.addAction("X", 0, 5);
navigation.addAction("V", 5, 5);
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// frame.getContentPane().add(new JTextField(), BorderLayout.SOUTH);
frame.getContentPane().add(contentPane);
frame.setSize(600, 600);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
此代码在Windows上进行了测试，其中事件的顺序是keyPressed，keyPressed，keyPressed ... keyReleased。然而，我认为在Mac（或Unix）上，事件的顺序是keyPressed，keyReleased，keyPressed，keyReleased ...所以我不确定这段代码是否会比当前代码更好地工作。
只是FYI，这个引用来自我，但我不是OP。 – syb0rg 2013-05-03 20:53:05
一个好主意是为你想要跟踪的键设置布尔值，然后在按键事件中激活其中一个布尔值，然后在释放的键上停用它。它将消除按键的滞后，并允许多个按键！
我最初有一个关于键绑定的答案，但经过一些测试后，我发现他们仍然有相同的口吃问题。然而，对于其他的东西+1。 – syb0rg 2013-05-02 01:47:42
@ syb0rg这就是为什么你需要那个小旗子;）。最后一个例子展示了允许按键事件应用加速度增量的简洁想法，按下时间越长，增量增加的越多，直到它被释放并且增量反转，随着时间推移减慢对象;） – MadProgrammer 2013-05-02 01:51:55
@ syb0rg添加了一个简单的例子来演示原理;） – MadProgrammer 2013-05-02 01:58:57