@Eng.Fouad 对他有一个很好的点 +1，虽然我个人从来没有因为这个确切的原因需要这个，但你的移动方法可能非常占用 cpu。
JPanel只是为了展示一个使用您的游戏逻辑的示例（从我的评论中扩展），如果正确实施，则不需要revalidate()玩家移动（通过setLocation(..)），这也可能导致大量延迟，尤其是在有很多组件的情况下。正如您将看到我的GamePanel扩展JPanel和使用Null/Absolute布局（但在游戏中我们想要更多地控制布局）。
也用KeyBindings 向你展示它们的用途。
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;
import javax.swing.border.LineBorder;
public class GameLogic {
public GameLogic() {
initComponents();
}
private void initComponents() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Entity entity = new Entity("Player", 100, 100, 50, 50);//starting location 100,100 and width/height 50x50
GamePanel gp = new GamePanel(300, 300);
gp.addEntity(entity);
setGamePanelKeyBindings(gp, entity);
frame.add(gp);
frame.pack();
frame.setVisible(true);
}
private void setGamePanelKeyBindings(GamePanel gp, final Entity entity) {
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("D"), "D pressed");
gp.getActionMap().put("D pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.move(Entity.RIGHT);
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("A"), "A pressed");
gp.getActionMap().put("A pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.move(Entity.LEFT);
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("W"), "W pressed");
gp.getActionMap().put("W pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.move(Entity.UP);
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("S"), "S pressed");
gp.getActionMap().put("S pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.move(Entity.DOWN);
}
});
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new GameLogic();
}
});
}
}
class Entity extends JPanel {
private int width = 50, height = 50;
private int speed = 5;
public static final int UP = 1, DOWN = 2, LEFT = 3, RIGHT = 4;
public Entity(String text, int x, int y, int width, int height) {
this.width = width;
this.height = height;
add(new JLabel(text));
setBorder(new LineBorder(Color.BLACK));
setBounds(x, y, width, height);
}
public void move(int direction) {
switch (direction) {
case UP:
setLocation(getX(), getY() - speed);
break;
case DOWN:
setLocation(getX(), getY() + speed);
break;
case LEFT:
setLocation(getX() - speed, getY());
break;
case RIGHT:
setLocation(getX() + speed, getY());
break;
}
}
@Override
public void setBounds(int x, int y, int w, int h) {
super.setBounds(x, y, width, height);
}
@Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
grphcs.setColor(Color.CYAN);
grphcs.fillRect(0, 0, getWidth(), getHeight());
}
}
class GamePanel extends JPanel {
private int width, height;
GamePanel(int w, int h) {
setLayout(null);
width = w;
height = h;
}
@Override
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
public void addEntity(Entity e) {
add(e);
}
@Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
grphcs.setColor(Color.GREEN);
grphcs.fillRect(0, 0, getWidth(), getHeight());
}
}
对不起，我无法阻止自己
如果您有兴趣，这里有一些高级版本，可以暂停游戏循环，可以设置帧速率等，2个键（例如W并且D 可能同时按下，从而导致JPanel对角线移动）：
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import javax.swing.AbstractAction;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;
import javax.swing.border.LineBorder;
public class GameLogic {
public GameLogic() {
initComponents();
}
final GamePanel gp = new GamePanel(500, 500);
private void initComponents() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Entity entity = new Entity("Player", 100, 100, 100, 100);
gp.addEntity(entity);
setGamePanelKeyBindings(gp, entity);
frame.add(gp);
frame.pack();
frame.setVisible(true);
//start the game loop which will repaint the screen
runGameLoop();
}
//Starts a new thread and runs the game loop in it.
public void runGameLoop() {
Thread loop = new Thread(new Runnable() {
@Override
public void run() {
gp.running = true;
gp.gameLoop();
}
});
loop.start();
}
private void setGamePanelKeyBindings(GamePanel gp, final Entity entity) {
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("D"), "D pressed");
gp.getActionMap().put("D pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.RIGHT = true;
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("A"), "A pressed");
gp.getActionMap().put("A pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.LEFT = true;
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("W"), "W pressed");
gp.getActionMap().put("W pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.UP = true;
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("S"), "S pressed");
gp.getActionMap().put("S pressed", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.DOWN = true;
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("released D"), "D released");
gp.getActionMap().put("D released", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.RIGHT = false;
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("released A"), "A released");
gp.getActionMap().put("A released", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.LEFT = false;
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("released W"), "W released");
gp.getActionMap().put("W released", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.UP = false;
}
});
gp.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("released S"), "S released");
gp.getActionMap().put("S released", new AbstractAction() {
@Override
public void actionPerformed(ActionEvent ae) {
entity.DOWN = false;
}
});
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new GameLogic();
}
});
}
}
class Entity extends JPanel {
private int width = 50, height = 50;
private int speed = 5;
public boolean UP = false, DOWN = false, LEFT = false, RIGHT = false;
public Entity(String text, int x, int y, int width, int height) {
this.width = width;
this.height = height;
add(new JLabel(text));
setBorder(new LineBorder(Color.BLACK));
setBounds(x, y, width, height);
}
public void move() {
if (UP) {
setLocation(getX(), getY() - speed);
}
if (DOWN) {
setLocation(getX(), getY() + speed);
}
if (LEFT) {
setLocation(getX() - speed, getY());
}
if (RIGHT) {
setLocation(getX() + speed, getY());
}
}
@Override
public void setBounds(int x, int y, int w, int h) {
super.setBounds(x, y, width, height);
}
@Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
grphcs.setColor(Color.CYAN);
grphcs.fillRect(0, 0, getWidth(), getHeight());
}
}
class GamePanel extends JPanel {
private int width, height;
private int frameCount = 0;
private int fps = 0;
public static boolean running = false, paused = false;
final ArrayList<Entity> entities = new ArrayList<>();
GamePanel(int w, int h) {
setLayout(null);
width = w;
height = h;
}
@Override
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
public void addEntity(Entity e) {
add(e);
entities.add(e);
}
@Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
grphcs.setColor(Color.GREEN);
grphcs.fillRect(0, 0, getWidth(), getHeight());
grphcs.setColor(Color.BLACK);
grphcs.drawString("FPS: " + fps, 5, 10);
frameCount++;
}
//Only run this in another Thread!
public void gameLoop() {
//This value would probably be stored elsewhere.
final double GAME_HERTZ = 30.0;
//Calculate how many ns each frame should take for our target game hertz.
final double TIME_BETWEEN_UPDATES = 1000000000 / GAME_HERTZ;
//At the very most we will update the game this many times before a new render.
//If you're worried about visual hitches more than perfect timing, set this to 1.
final int MAX_UPDATES_BEFORE_RENDER = 5;
//We will need the last update time.
double lastUpdateTime = System.nanoTime();
//Store the last time we rendered.
double lastRenderTime = System.nanoTime();
//If we are able to get as high as this FPS, don't render again.
final double TARGET_FPS = 60;
final double TARGET_TIME_BETWEEN_RENDERS = 1000000000 / TARGET_FPS;
//Simple way of finding FPS.
int lastSecondTime = (int) (lastUpdateTime / 1000000000);
while (running) {
double now = System.nanoTime();
int updateCount = 0;
if (!paused) {
//Do as many game updates as we need to, potentially playing catchup.
while (now - lastUpdateTime > TIME_BETWEEN_UPDATES && updateCount < MAX_UPDATES_BEFORE_RENDER) {
updateGame();
lastUpdateTime += TIME_BETWEEN_UPDATES;
updateCount++;
}
//If for some reason an update takes forever, we don't want to do an insane number of catchups.
//If you were doing some sort of game that needed to keep EXACT time, you would get rid of this.
if (now - lastUpdateTime > TIME_BETWEEN_UPDATES) {
lastUpdateTime = now - TIME_BETWEEN_UPDATES;
}
drawGame();
lastRenderTime = now;
//Update the frames we got.
int thisSecond = (int) (lastUpdateTime / 1000000000);
if (thisSecond > lastSecondTime) {
System.out.println("NEW SECOND " + thisSecond + " " + frameCount);
fps = frameCount;
frameCount = 0;
lastSecondTime = thisSecond;
}
//Yield until it has been at least the target time between renders. This saves the CPU from hogging.
while (now - lastRenderTime < TARGET_TIME_BETWEEN_RENDERS && now - lastUpdateTime < TIME_BETWEEN_UPDATES) {
//allow the threading system to play threads that are waiting to run.
Thread.yield();
//This stops the app from consuming all your CPU. It makes this slightly less accurate, but is worth it.
//You can remove this line and it will still work (better), your CPU just climbs on certain OSes.
//FYI on some OS's this can cause pretty bad stuttering. Scroll down and have a look at different peoples' solutions to this.
//On my OS it does not unpuase the game if i take this away
try {
Thread.sleep(1);
} catch (Exception e) {
}
now = System.nanoTime();
}
}
}
}
private void updateGame() {
for (Entity e : entities) {
e.move();
}
}
private void drawGame() {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
repaint();
}
});
}
}