我的重力等级有问题，每当用户跳跃时，它应该改变 y 坐标，直到到达底座，但是当我反复按下跳跃按钮 (W) 时，它会出现错误，并且立方体会继续下降到底座下方。
主类:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
@SuppressWarnings("serial")
public class Frame extends JFrame implements Runnable{ //main class
static Panel panel;
static Frame frame;
//CONSTRUCTOR
Frame(){ //constructor
super("Game Frame");
setLayout(new GridLayout(1,1));
panel = new Panel();
add(panel);
} //constructor
public static void main (String args[]){ //main method
frame = new Frame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.setResizable(true);
frame.setSize(500,300);
frame.setLocationRelativeTo(null);
Thread T1 = new Thread(frame);
T1.start();
} //main method
public void run(){ //run method
frame.addKeyListener(new KeyListener(){ //key listener method
@Override
public void keyPressed(KeyEvent arg0) { //key pressed
switch(arg0.getKeyChar()){
//A (LEFT)
case 'a':
panel.x -= 10;
panel.repaint();break;
//D (RIGHT)
case 'd':
panel.x += 10;
panel.repaint();break;
//W (UP)
case 'w':
panel.y -= 40;
panel.repaint();
Thread T1 = new Thread(new Gravity());
T1.start();
} //switch
} //key pressed method
@Override
public void keyReleased(KeyEvent arg0) {}
@Override
public void keyTyped(KeyEvent arg0) {}
}); //key listener method
} //run method
} //main class
面板类:
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
@SuppressWarnings("serial")
public class Panel extends JPanel{ //class
static BufferedImage bg;
static int x = 20;
static int y = 195;
//PAINT METHOD
public void paint(Graphics g){ //method
super.paint(g);
g.setColor(Color.ORANGE);
this.setBackground(Color.BLACK);
//IMPORTING IMAGES
try {
bg = ImageIO.read(getClass().getResourceAsStream("Background.png"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//DRAWING GAME
g.drawImage(bg, 0, 0,500,275,null);
g.fillRect(x, y, 50, 50);
} //method
} //class
重力等级:
public class Gravity implements Runnable{ //class
@Override
public void run() { //run method
while(Frame.panel.y != 195){ //while loop
try {
Thread.sleep(100);
} catch (InterruptedException e) { //catch exception
// TODO Auto-generated catch block
e.printStackTrace();
} //catch exception
Frame.panel.y += 5;
Frame.panel.repaint();
} //while loop
} //run method
} //class
最佳答案
我建议您不要创建多个线程，而应重用一个线程。可能发生的情况是两个线程修改了 Frame.panel.y。第一个将其移动到 195，而第二个正在 sleep ，然后第二个将其移动到 200 并且满足您的 !=195 条件。稍后在框架之外绘画会发生崩溃。一个简单的解决方法是将“while(Frame.panel.y != 195)”替换为“while(Frame.panel.y < 195)”
关于Java重力错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41198043/