【发布时间】：2018-06-21 19:31:43
【问题描述】：
我希望使用 Swing 创建一个简单的井字游戏 GUI 游戏；
我创建了名为TicTacToe 的JFrame，并将JPanel 放入其中，名为gamePanel 和GridLayout(3,3)。然后我为我的按钮创建了一个名为buttons[][] 的按钮数组，我将在其中放置X 或O 的图标。然后我生成了 9 个按钮和
增加了逻辑。 JPanel 代码：
public class gamePanel extends JPanel {
XOButton buttons[][] = new XOButton[3][3];
boolean isX;
public gamePanel() {
setLayout(new GridLayout(3, 3));
for(int i = 0; i < 3; i++){
for(int j = 0; j < 3; j++) {
buttons[i][j] = new XOButton();
buttons[i][j].setIcon(null);
add(buttons[i][j]);
}
}
isX = true;
}
private class XOButton extends JButton {
ImageIcon X, O;
public XOButton() {
X = new ImageIcon(gamePanel.this.getClass().getResource("X.png"));
O = new ImageIcon(gamePanel.this.getClass().getResource("O.png"));
addActionListener(this::actionPerformed);
}
public int getValue(XOButton btn){
if(btn.getIcon().toString().equals(null)){
return 0;
}
if(btn.getIcon().toString().equals(X.toString())){
return 1;
}
if(btn.getIcon().toString().equals(O.toString())){
return 2;
}
return 0;
}
public void actionPerformed(ActionEvent e) {
if(getIcon() != null) return;
if (isX) {
setIcon(X);
isX = false;
checkWinner();
} else {
setIcon(O);
isX = true;
checkWinner();
}
}
public void checkWinner(){
for(int i = 0; i < 3; i++){
if(getValue(buttons[i][0]) != 0 && getValue(buttons[i][0]) == getValue(buttons[i][1])
&& getValue(buttons[i][1]) == (getValue(buttons[i][2]))) {
if (getValue(buttons[i][0]) == 1) {
JOptionPane.showMessageDialog(null, X);
return;
} else if (getValue(buttons[i][0]) == 2) {
JOptionPane.showMessageDialog(null, O);
return;
}
}
}
}
}
}
我想知道我是否可以得到问题的答案（请！）：
如您所见，我创建了名为checkWinner 的程序，但它只检查按钮图标是否在一行中相等。但是当我使用这段代码时，它只适用于第一行。第二个和第三个被忽略，直到我填充第一行的前两个按钮。当代码工作时，它应该显示带有 X 或 O 图像的消息（取决于谁是赢家）。
Image where it works fine in the first row 和
Image where it is not working (until I will fill first row for a half)
当我在第二张图片中填充第一行时，它将同时显示两个messageDialogs 和X 和O 图像。
我做错了什么？ 我还将感谢有关我的代码的答案和 cmets，这太糟糕了，我想提高我的技能。 感谢关注。
编辑：按下任何按钮时出现此异常：
`Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at gamePanel$XOButton.getValue(gamePanel.java:34)
at gamePanel$XOButton.checkWinner(gamePanel.java:61)
at gamePanel$XOButton.actionPerformed(gamePanel.java:51)
at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:270)
at java.desktop/java.awt.Component.processMouseEvent(Component.java:6589)
at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
at java.desktop/java.awt.Component.processEvent(Component.java:6354)
at java.desktop/java.awt.Container.processEvent(Container.java:2260)
at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4966)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2318)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4798)
at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4906)
at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4535)
at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4476)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2304)
at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2772)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4798)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
at java.desktop/java.awt.EventQueue.access$600(EventQueue.java:97)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:97)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
`
【问题讨论】：
-
您应该运行调试器或让 checkWinner 在启动时转储它的参数。乍一看，我没有看到任何会阻止它工作的东西，但我不确定你的板子是否正确填写。
-
我忘了告诉我按下任何按钮时都会出现这些错误。
-
获胜条件有8个。不要迭代只是检查每个案例。 HORIZ:[0][0],[1][0],[2][0] [0][1],[1][1],[2][1] [0][2],[ 1][2],[2][2] 垂直：[0][0],[0][1],[0][2] [1][0],[1][1],[1 ][2] [2][0],[2][1],[2][2] 诊断：[0][0],[1][1],[2][2] [2][ 2]，[1][1]，[0][0]。检查所有元素是否相等