我写了一个简单的 2D 游戏——推箱子(http://www.game-sokoban.com/)。我在屏幕上有一个二维字段。单独的JPanel Board 负责。
import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.net.URL;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
import java.io.IOException;
import java.util.Properties;
public class Board extends JPanel {
private static final String CONFIG_FILE_NAME = "ImageConfig.txt";
/** length px of a square cell */
private static final int SPACE = 20;
private Properties properties;
private Map<Status, Image> Images = null;
private Status[][] cells = null;
private BufferedImage canvas = null;
private Graphics2D g2d = null;
public Board() {
Properties properties = new Properties();
try {
//load a properties file
properties.load(ClassLoader.getSystemResourceAsStream(CONFIG_FILE_NAME));
}
catch (IOException ex) {
ex.printStackTrace();
}
Images = new HashMap<Status, Image>();
for (String key : properties.stringPropertyNames()) {
switch (key) {
case "AREA" : {
Images.put(Status.AREA, null);
break;
}
case "BAGGAGE" : {
Images.put(Status.BAGGAGE, null);
break;
}
case "FREE" : {
Images.put(Status.FREE, null);
break;
}
case "SOKO" : {
Images.put(Status.SOKO, null);
break;
}
case "WALL" : {
Images.put(Status.WALL, null);
break;
}
}
}
this.properties = properties;
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g;
g2d.drawImage(this.canvas, cells.length, cells[0].length, this);
}
public void setSize_(int height, int width) {
canvas = new BufferedImage(width * SPACE, height * SPACE, BufferedImage.TYPE_INT_RGB);
g2d = canvas.createGraphics();
setPreferredSize(new Dimension(width * SPACE, height * SPACE));
cells = new Status[height][width];
}
public void drawCell(int i, int j, Status status) {
cells[i][j] = status;
try {
g2d.drawImage(getImage(cells[i][j]), j * SPACE, i * SPACE, this);
}
catch (Exception e) {
e.printStackTrace();
}
repaint();
}
}
每次移动时,场上的玩家都会更新,只有两个或三个单元格。我不想重绘所有字段,并且只调用 g2d 上的 drawImage (...) 的一些调用,并且更改就在屏幕上显示。至于我来实现它(没有paintComponent())?