这里的想法是创建一个盒子网格。在黑色网格下面是另一个多色盒子网格。当你点击一个方框时，它的面具会消失，显示下方的彩色方框。然后，如果颜色匹配hurray，则单击第二个框，否则则游戏继续。这是代码。
import java.applet.Applet;
import java.awt.Button;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class GuessingGame extends Applet{
/**
*
*/
private static final long serialVersionUID = 1L;
private final int START_X = 20;
private final int START_Y = 40;
private final int ROWS = 4;
private final int COLS = 4;
private final int BOX_WIDTH = 20;
private final int BOX_HEIGHT = 20;
//this is used to keep track of boxes that have been matched.
private boolean matchedBoxes[][];
//this is used to keep track of two boxes that have been clicked.
private MaskableBox chosenBoxes[];
private MaskableBox boxes[][];
private Color boxColors[][];
private Button resetButton;
public void init() {
boxes = new MaskableBox[ROWS][COLS];
boxColors = new Color[ROWS][COLS];
resetButton = new Button("Reset Colors");
resetButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
randomizeColors();
buildBoxes();
repaint();
}
});
add(resetButton);
//separate building colors so we can add a button later
//to re-randomize them.
randomizeColors();
buildBoxes();
}
public void paint(Graphics g) {
for (int row =0; row < boxes.length; row ++) {
for (int col = 0; col < boxes[row].length; col++) {
if(boxes[row][col].isClicked()) {
//boxes[row][col].setMaskColor(Color.black);
//boxes[row][col].setMask(!boxes[row][col].isMask());
//boxes[row][col].setClicked(false);
//}
if (!matchedBoxes[row][col]) {
gameLogic(boxes[row][col]);
//boxes[row][col].draw(g);
}
}
}
}
//loop through the boxes and draw them.
for (int row = 0; row < boxes.length; row++) {
for (int col = 0; col < boxes[row].length; col++) {
boxes[row][col].draw(g);
}
}
}
public void gameLogic(MaskableBox box) {
if ((chosenBoxes[0] != null)&&(chosenBoxes[1] != null)) {
if(chosenBoxes[0].getBackColor() == chosenBoxes[1].getBackColor()) {
for (int i=0; 0 < chosenBoxes.length; i++ ) {
for(int row = 0; row < boxes.length; row++) {
for(int col = 0; col < boxes[row].length; col++) {
if( boxes[row][col] == chosenBoxes[i] ) {
System.out.println("boxes [row][col] == chosenBoxes[] at index: " + i );
matchedBoxes[row][col] = true;
break;
}
}
}
}
}else {
chosenBoxes[0].setMask(true);
chosenBoxes[1].setMask(true);
}
chosenBoxes = new MaskableBox[2];
}else {
if (chosenBoxes[0] == null) {
chosenBoxes[0] = box;
chosenBoxes[0].setMask(false);
return;
}else{
if (chosenBoxes[1] == null) {
chosenBoxes[1] = box;
chosenBoxes[1].setMask(false);
}
}
}
}
private void removeMouseListeners() {
for(int row = 0; row < boxes.length; row ++) {
for(int col = 0; col < boxes[row].length; col++) {
removeMouseListener(boxes[row][col]);
}
}
}
private void buildBoxes() {
// need to clear any chosen boxes when building new array.
chosenBoxes = new MaskableBox[2];
// create a new matchedBoxes array
matchedBoxes = new boolean [ROWS][COLS];
removeMouseListeners();
for(int row = 0; row < boxes.length; row++) {
for(int col = 0; col < boxes[row].length; col++) {
boxes[row][col] =
new MaskableBox(START_X + col * BOX_WIDTH,
START_Y + row * BOX_HEIGHT,
BOX_WIDTH,
BOX_HEIGHT,
Color.gray,
boxColors[row][col],
true,
true,
this);
addMouseListener(boxes[row][col]);
}
}
}
private void randomizeColors() {
int[] chosenColors = {0,0,0,0,0,0,0,0};
Color[] availableColors = {Color.red, Color.blue, Color.green,
Color.yellow, Color.cyan, Color.magenta, Color.pink, Color.orange };
for(int row = 0; row < boxes.length; row++) {
for (int col = 0; col < boxes[row].length; col++) {
for (;;) {
int rnd = (int) (Math.random() * 8);
if (chosenColors[rnd]< 2) {
chosenColors[rnd]++;
boxColors[row][col] = availableColors[rnd];
break;
}
}
}
}
}
}
这是第二批包含maskablebox的代码
import java.awt.Color;
import java.awt.Container;
import java.awt.Graphics;
public class MaskableBox extends ClickableBox {
private boolean mask;
private Color maskColor;
Container parent;
public MaskableBox(int x, int y, int width, int height, Color borderColor,
Color backColor, boolean drawBorder, boolean mask, Container parent ) {
super(x, y, width, height, borderColor, backColor, drawBorder, parent);
this.parent = parent;
this.mask = mask;
}
public void draw(Graphics g) {
if(mask=false) {
super.draw(g);
// setOldColor(g.getColor());
// g.setColor(maskColor);
// g.fillRect(getX(),getY(),getWidth(), getHeight());
// if(isDrawBorder()) {
// g.setColor(getBorderColor());
// g.drawRect(getX(),getY(),getWidth(),getHeight());
// }
// g.setColor(getOldColor());
}else {
if(mask=true) {
//super.draw(g);
setOldColor(g.getColor());
g.setColor(maskColor);
g.fillRect(getX(),getY(),getWidth(), getHeight());
if(isDrawBorder()) {
g.setColor(getBorderColor());
g.drawRect(getX(),getY(),getWidth(),getHeight());
}
g.setColor(getOldColor());
}
}
}
public boolean isMask() {
return mask;
}
public void setMask(boolean mask) {
this.mask = mask;
}
public Color getMaskColor() {
return maskColor;
}
public void setMaskColor(Color maskColor) {
this.maskColor = maskColor;
}
}
我现在收到这些错误消息。
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
at GuessingGame.gameLogic(GuessingGame.java:74)
at GuessingGame.paint(GuessingGame.java:55)
at java.awt.Container.update(Container.java:1801)
at sun.awt.RepaintArea.updateComponent(RepaintArea.java:239)
at sun.awt.RepaintArea.paint(RepaintArea.java:216)
at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:306)
at java.awt.Component.dispatchEventImpl(Component.java:4706)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4460)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
答案 0 :(得分：8)
看，你在那里看到的错误信息叫做：“堆栈跟踪”
它包含有关错误内容的非常有用的信息：
Exception in thread "AWT-EventQueue-1" java.lang.ArrayIndexOutOfBoundsException: 2
at GuessingGame.gameLogic(GuessingGame.java:77) // This is where the error happened
at GuessingGame.paint(GuessingGame.java:55) // This is your code
at java.awt.Container.update(Container.java:1801) // not your code
at sun.awt.RepaintArea.updateComponent(RepaintArea.java:239) // not your code
如果您看到它显示：GuessingGame.java:77表示错误发生在第77行的文件GuessingGame.java中。其他文件不在您的源代码中（Container.java和Repaint.java）所以，他们不是问题发生的地方。
在第77行的GuessingGame.java中，您试图访问数组边界之外的索引（因此ArrayIndexOutOfBoundException），数字{{1它是你试图使用的索引。
根据该信息，您可以查看源代码并查看第77行（至少来自发布的代码）：
2所以， if( boxes[row][col] == chosenBoxes[i] ) {
不是问题（它的大小是4，它被声明为boxes，ROWS和COLS都被声明为4）。所以责任人必须是：boxes = new MaskableBox[ROWS][COLS];
它被初始化为：
chosenBoxes大小 2 ，这意味着唯一有效的索引是chosenBoxes = new MaskableBox[2];
和0。当您尝试使用index = 2时，会引发异常。
现在记住这些信息，您可能会搜索可能导致该信息的代码。
其他答案指出原因是
1上面只有3行！它读取，“虽然零低于或等于2 ......”，它将始终返回true，因为0将始终为＆lt;比2。
所以，你只需要修复那个部分并重新测试。
我希望这个解释可以帮助你解决将来的这类问题。学会阅读堆栈跟踪非常重要。
我甚至可以想象未来的首字母缩略词：RTFST;）
答案 1 :(得分：2)
在你的gameLogic方法中，chosenBoxes有两个元素，但你循环到i <= chosenBoxes.length（循环i = 0,1,2）。这就是你得到例外的原因。将其更改为i < chosenBoxes.length。
事实上，你有：
for (int i=0; 0 <= chosenBoxes.length; ++i ) {
将其更改为：
for (int i=0; i < chosenBoxes.length; i++ ) {
我不确定你为什么在该循环中为前缀递增i。
答案 2 :(得分：0)
下面：
for (int i=0; 0 <= chosenBoxes.length; ++i ) {
你的情况总是如此;）