我一直在关注 Java Game Programming for Beginners教程系列,并希望通过应用背景图像进行实验。不幸的是,当我通过 paintComponent
方法渲染它时,它会随着我的 sprite 移动(尽管连续移动一个单位而不是五个);当我通过 paint 方法渲染它时,我得到一个奇怪的、闪烁的框,它与 JFrame
的 setBackground (color)
属性中指定的颜色相匹配,它随着 Sprite 与先前实例的 Sprite 相同(在 paintComponent
中)。
我如何编码图像以保持静态,就像背景应该的那样?
代码:
public class JavaGame extends JFrame{
int x, y;
private Image dbImage;
private Graphics dbg;
Image ghost;
Image bg;
public class AL extends KeyAdapter{
public void keyPressed(KeyEvent e){
int keyCode = e.getKeyCode();
if(keyCode == e.VK_LEFT){
if(x <= 8)
x = 8;
else
x += -5;
}
if(keyCode == e.VK_RIGHT){
if(x >= 235)
x = 235;
else
x += +5;
}
if(keyCode == e.VK_UP){
if(y <= 18)
y = 18;
else
y += -5;
}
if(keyCode == e.VK_DOWN){
if(y >= 235)
y = 235;
else
y += +5;
}
}
public void keyReleased(KeyEvent e){
}
}
public JavaGame(){
//Load images
ImageIcon i = new ImageIcon("C:/Users/Taylor/workspace/Java game/src/ghost.png");
ghost = i.getImage();
ImageIcon j = new ImageIcon("C:/Users/Taylor/workspace/Java game/src/bg.png");
bg = j.getImage();
//Game properties
addKeyListener(new AL());
setTitle("Java Game");
setSize(500, 500);
setResizable(false);
setVisible(true);
setBackground(Color.GRAY);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
x = 150;
y = 150;
}
public void paint(Graphics g){
g.drawImage(bg, 0, 0, null);
dbImage = createImage(getWidth(), getHeight());
dbg = dbImage.getGraphics();
paintComponent(dbg);
g.drawImage(dbImage, x, y, this);
}
public void paintComponent(Graphics g){
g.setColor(Color.WHITE);
g.drawImage(ghost, x, y, this);
repaint();
}
public static void main(String[] args) {
new JavaGame();
}
图片:
最佳答案
您是随机复制/粘贴代码吗?这就是它的样子。该代码有太多奇怪的方面,我没有将它们全部记录下来(也许对代码审查来说是一个很好的方面)。该示例使用异步方法加载图像(为了获得动画图像,动画)。使用 ImageIO.read(URL)
以同步方式加载静态图像。
这里有一些简短的提示:
- 到部署时,图像可能会成为嵌入式资源,
File
对象将无法访问这些资源。将它们添加到运行时类路径并通过 URL 访问它们。 - 应在 EDT 上启动和更改 Swing GUI(请参阅对
main()
的更改)。 - 始终在方法开始时调用
super.paint(g);
(或paintComponent(g)
)。 - 不要扩展框架,不要绘制到顶级组件。而是扩展面板并覆盖
paintComponent()
。将面板添加到框架。
代码
import java.awt.*;
import java.awt.event.*;
import java.net.URL;
import javax.swing.*;
public class JavaGame extends JPanel {
int x, y;
private Image dbImage;
private Graphics dbg;
Image ghost;
Image bg;
public class AL extends KeyAdapter {
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == e.VK_LEFT) {
if (x <= 8)
x = 8;
else
x += -5;
}
if (keyCode == e.VK_RIGHT) {
if (x >= 235)
x = 235;
else
x += +5;
}
if (keyCode == e.VK_UP) {
if (y <= 18)
y = 18;
else
y += -5;
}
if (keyCode == e.VK_DOWN) {
if (y >= 235)
y = 235;
else
y += +5;
}
}
public void keyReleased(KeyEvent e) {
}
}
public JavaGame() throws Exception {
// Load images
//ImageIcon i = new ImageIcon(
// "C:/Users/Taylor/workspace/Java game/src/ghost.png");
URL urlGhost = new URL("http://1point1c.org/gif/thum/plnttm.gif");
ghost = Toolkit.getDefaultToolkit().createImage(urlGhost);
//ImageIcon j = new ImageIcon(
// "C:/Users/Taylor/workspace/Java game/src/bg.png");
URL urlBG = new URL("http://pscode.org/media/stromlo2.jpg");
bg = Toolkit.getDefaultToolkit().createImage(urlBG);
setFocusable(true);
// Game properties
addKeyListener(new AL());
x = 150;
y = 150;
ActionListener al = new ActionListener() {
public void actionPerformed(ActionEvent ae) {
repaint();
}
};
Timer timer = new Timer(50,al);
timer.start();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(bg, 0, 0, null);
//dbImage = createImage(getWidth(), getHeight());
//dbg = dbImage.getGraphics();
//paintComponent(dbg);
g.drawImage(dbImage, x, y, this);
g.setColor(Color.WHITE);
g.drawImage(ghost, x, y, this);
//repaint();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
JFrame f = new JFrame("Java Game");
f.setSize(500, 500);
f.setResizable(false);
f.setVisible(true);
f.setBackground(Color.GRAY);
f.setContentPane(new JavaGame());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
关于java - 简单游戏的背景图片?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12082660/