所以我正在创建一个侧滚动条，我试图在另一个图像的位置绘制一个图像。
我的背景图像是 5000 x 500，假设我想在背景图像的 500、50 处绘制 25x25 的图像。我该怎么做？
到目前为止，我已经尝试过：
Coins c = new Coins(img.getWidth(this) - 4500, img.getHeight(this) - 250);
但这只是在帧的 500、50 处绘制它，因此当我向右滚动时它在图像上“移动”。我想在向右滚动一次后，将硬币图像绘制在图像的 500,50 处，仍然是帧的 495、50 处。
我也可以使用背景图像的 getGraphics 并在其上绘制较小的图像，但我认为因为我在创建对象期间设置了要绘制的点，所以我不能这样做。
除了上下，角色不会移动，只是背景滚动，所以我希望硬币像背景一样移动。
图片：（无法嵌入，因为我没有 10 个代表点） http://dl.dropbox.com/u/47632315/char.png http://dl.dropbox.com/u/47632315/coin .png http://dl.dropbox.com/u/47632315/sideScrollerBG.png
和 SSCCE：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.*;
import java.awt.image.ImageObserver;
import java.io.IOException;
import javax.imageio.ImageIO;
public class SideScroller extends JPanel implements KeyListener {
public static void main(String args[]) throws Exception {
SideScroller f = new SideScroller("Side Scroller");
}
JFrame f = new JFrame();
int x = 0;
int y = 0;
int k = 10;
int j = 50;
int characterY = 351;
boolean canJump = true;
boolean keyPressed[] = new boolean[3];
Image img;
Image character;
Coins c = new Coins(x + 500, y + 350);
public SideScroller(String s) throws MalformedURLException, IOException {
img = ImageIO.read(new URL("http://dl.dropbox.com/u/47632315/sideScrollerBG.png"));
character = ImageIO.read(new URL("http://dl.dropbox.com/u/47632315/char.png"));
f.setTitle(s);
// don't use 'magic numbers' when descriptive constants are defined!
//f.setDefaultCloseOperation(3);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setResizable(false);
// Better to ask when loaded.
//setPreferredSize(new Dimension(1000, 500));
setPreferredSize(new Dimension(1000, img.getHeight(this)));
f.add(this);
f.pack();
// usually harmful, rarely necessary.
// f.setLayout(null);
// Looks like a splash screen
//f.setLocationRelativeTo(null);
// located by platform default, best.
f.setLocationByPlatform(true);
f.addKeyListener(this);
getKeys();
// should be done last
f.setVisible(true);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, x, y, this);
g.drawImage(character, 50, characterY, this);
c.paint(g, this);
}
@Override
public void keyTyped(KeyEvent e) {
}
@Override
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == KeyEvent.VK_ESCAPE) {
System.exit(0);
}
if (keyCode == KeyEvent.VK_RIGHT) {
keyPressed[0] = true;
}
if (keyCode == KeyEvent.VK_LEFT) {
keyPressed[1] = true;
}
if (canJump) {
if (keyCode == KeyEvent.VK_SPACE) {
// better to use a javax.swing.Timer here
new Thread(new Runnable() {
public void run() {
canJump = false;
for (double i = 0; i <= 5.1; i += .2) {
characterY = (int) (k * i * i - j * i + 351);
f.repaint();
System.out.println(characterY);
System.out.println(canJump);
try {
Thread.sleep(25);
} catch (InterruptedException e) {
System.err.println(e);
}
}
repaint();
canJump = true;
}
}).start();
}
}
}
@Override
public void keyReleased(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == KeyEvent.VK_RIGHT) {
keyPressed[0] = false;
}
if (keyCode == KeyEvent.VK_LEFT) {
keyPressed[1] = false;
}
}
public void getKeys() {
new Thread(new Runnable() {
public void run() {
while (true) {
if (keyPressed[0]) {
x -= 5;
repaint();
}
if (keyPressed[1]) {
if (x != 0) {
x += 5;
repaint();
}
}
try {
Thread.sleep(25);
} catch (InterruptedException e) {
System.err.println(e);
}
}
}
}).start();
}
}
class Coins extends pickUpObject {
Image coin;
public Coins(int x, int y) throws MalformedURLException, IOException{
super(x, y);
super.x = x;
super.y = y;
coin = ImageIO.read(new URL("http://dl.dropbox.com/u/47632315/coin.png"));
}
public void paint(Graphics g, ImageObserver o){
g.drawImage(coin, x, y, o);
}
}
abstract class pickUpObject {
int x, y;
public pickUpObject(int x, int y){
}
public abstract void paint(Graphics g, ImageObserver o);
}
