我正在尝试制作一个简单的火炮游戏，并在单击按钮时打印一个在屏幕上以弧线移动的圆圈。
单击时，我创建一个线程并计算“射弹”的位置并在计算 x 和 y 位置打印出一个圆圈。
当我从一个类执行代码时，它调用重绘并绘制“弹丸”的轨迹，但是当我设置一个单独的类来调用它并通过单击按钮将其打印出来时，它不会从环形。
当我自己执行下面的类时，会显示我想要的。
import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Pong4 extends JPanel implements Runnable {
/**
*
*/
private static final long serialVersionUID = 1L;
private ScreenLocation location;
private boolean renderBulit = false;
public static void main(String[] args)
{
Pong4 p = new Pong4();
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(p);
frame.setSize(800, 600);
frame.setVisible(true);
Thread thread = new Thread(p);
thread.start();
try {
thread.join();
} catch (InterruptedException ex) {
// TODO Auto-generated catch block
ex.printStackTrace();
}
}
public Pong4()
{
}
public ScreenLocation updatePosition(ScreenLocation location, double xSpeed, double ySpeed, double time)
{
return new ScreenLocation((int)(location.getX() + xSpeed * time), (int)(location.getY() - ySpeed * time));
}
@Override
public void run()
{
double time = 0;
location = new ScreenLocation(100, 400);
renderBulit = true;
double xSpeed = 50;
double ySpeed = 50;
while (location.getX() >= 0 && 800 > location.getX() && 400 >= location.getY())
{
repaint();
System.out.println("test");
try {
Thread.sleep(15);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
time += 0.01;
location = updatePosition(location, xSpeed, ySpeed, time);
ySpeed = ySpeed - Constants.GRAVITY * time;
}
renderBulit = false;
repaint();
}
@Override
public void paintComponent(Graphics g)
{
super.paintComponents(g);
Graphics2D g2d = (Graphics2D)g;
// Paint a gradient from top to bottom
GradientPaint gp = new GradientPaint( 0, 0, Color.BLACK,
0, getHeight( ), new Color(0, 0, 255).darker( ).darker() );
g2d.setPaint( gp );
g2d.fillRect( 0, 0, getWidth( ), getHeight( ) );
if (renderBulit)
{
// draw circle (color already set to foreground)
g.setColor(Color.red);
g.fillOval(location.getX(), location.getY(), 4, 4);
g.drawOval(location.getX(), location.getY(), 4, 4);
//Image image = new ImageIcon("src/au/com/tankwarz/view/resources/images/BULIT0.GIF").getImage();
//g.drawImage(image, location.getX(), location.getY(), this);
}
g2d.dispose();
}
public class ScreenLocation
{
private int x;
private int y;
public ScreenLocation (int x, int y)
{
this.x = x;
this.y = y;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
}
}
但是当我尝试以下操作时，它不会显示。
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import org.jdesktop.application.Application;
public class Pong3 extends JPanel{
public static void main(String[] args)
{
new Pong3();
}
private static final long serialVersionUID = 2944576178447230562L;
private JButton fireButton;
private JPanel controlsPanel;
private Pong4 pong;
public Pong3() {
super();
initGUI();
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(this);
frame.setSize(800, 600);
frame.setVisible(true);
}
private void initGUI() {
try {
this.setPreferredSize(new java.awt.Dimension(800, 600));
this.setSize(800, 600);
this.setLayout(null);
{
pong = new Pong4();
this.add(pong);
pong.setLayout(null);
pong.setBounds(0, 0, 800, 450);
}
{
controlsPanel = new JPanel();
this.add(controlsPanel);
GridBagLayout controlsPanelLayout = new GridBagLayout();
controlsPanelLayout.rowWeights = new double[] {0.1, 0.1, 0.1, 0.1};
controlsPanelLayout.rowHeights = new int[] {7, 7, 7, 7};
controlsPanelLayout.columnWeights = new double[] {0.1, 0.1, 0.1, 0.1};
controlsPanelLayout.columnWidths = new int[] {7, 7, 7, 7};
controlsPanel.setLayout(controlsPanelLayout);
controlsPanel.setBounds(0, 450, 800, 110);
controlsPanel.setName("controlsPanel");
{
fireButton = new JButton();
controlsPanel.add(fireButton, new GridBagConstraints(3, 1, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, new Insets(0, 0, 0, 0), 0, 0));
fireButton.setName("fireButton");
fireButton.setText("Fire");
fireButton.setPreferredSize(new java.awt.Dimension(104, 51));
fireButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Thread thread = new Thread(pong);
thread.start();
try {
thread.join();
} catch (InterruptedException ex) {
// TODO Auto-generated catch block
ex.printStackTrace();
}
}
});
}
}
Application.getInstance().getContext().getResourceMap(getClass()).injectComponents(this);
} catch (Exception e) {
e.printStackTrace();
}
}
}
希望有任何帮助说明为什么会这样。