我正在用 Java 制作国际象棋，现在，每当用户单击移动棋子时，我都会遇到更新棋盘的问题。我的游戏逻辑还远远没有完成，我只是想让 GUI 和 mouseListener 首先按照我希望的方式工作。我设计程序的方式是，棋子的位置全部存储在 8 x 8 字符串矩阵中。 64 由 64 个 JPanel 组成。每次用户单击移动棋子时，字符串矩阵都应该更新，并且 GUI 应该读取矩阵并相应更新。现在，矩阵正在更新，但 GUI 尚未更新。我不知道为什么会发生这种情况，也不知道如何解决它，有人可以帮助我吗？这是我的代码:
public class Chess extends JFrame implements MouseListener {
private static final long serialVersionUID = 1L;
private final BufferedImage whitePawnGUI = ImageIO.read(new File("img/WhitePawn.png"));
private final BufferedImage whiteKnightGUI = ImageIO.read(new File("img/WhiteKnight.png"));
private final BufferedImage whiteBishopGUI = ImageIO.read(new File("img/WhiteBishop.png"));
private final BufferedImage whiteRookGUI = ImageIO.read(new File("img/WhiteRook.png"));
private final BufferedImage whiteQueenGUI = ImageIO.read(new File("img/WhiteQueen.png"));
private final BufferedImage whiteKingGUI = ImageIO.read(new File("img/WhiteKing.png"));
private final BufferedImage blackPawnGUI = ImageIO.read(new File("img/BlackPawn.png"));
private final BufferedImage blackKnightGUI = ImageIO.read(new File("img/BlackKnight.png"));
private final BufferedImage blackBishopGUI = ImageIO.read(new File("img/BlackBishop.png"));
private final BufferedImage blackRookGUI = ImageIO.read(new File("img/BlackRook.png"));
private final BufferedImage blackQueenGUI = ImageIO.read(new File("img/BlackQueen.png"));
private final BufferedImage blackKingGUI = ImageIO.read(new File("img/BlackKing.png"));
private String[][] piecePositions = new String[8][8];
private JPanel[][] boardTiles = new JPanel[8][8];
private String lastSelected = "";
private int lastSelectedRow = 0;
private int lastSelectedCol = 0;
public Chess() throws IOException {
setTitle("Chess");
setDefaultCloseOperation(EXIT_ON_CLOSE);
setResizable(true);
setLayout(new BorderLayout());
getContentPane().setBackground(Color.white);
// white pieces
piecePositions[6][0] = "wp";
piecePositions[6][1] = "wp";
piecePositions[6][2] = "wp";
piecePositions[6][3] = "wp";
piecePositions[6][4] = "wp";
piecePositions[6][5] = "wp";
piecePositions[6][6] = "wp";
piecePositions[6][7] = "wp";
piecePositions[7][1] = "wn";
piecePositions[7][6] = "wn";
piecePositions[7][2] = "wb";
piecePositions[7][5] = "wb";
piecePositions[7][0] = "wr";
piecePositions[7][7] = "wr";
piecePositions[7][3] = "wq";
piecePositions[7][4] = "wk";
// black pieces
piecePositions[1][0] = "bp";
piecePositions[1][1] = "bp";
piecePositions[1][2] = "bp";
piecePositions[1][3] = "bp";
piecePositions[1][4] = "bp";
piecePositions[1][5] = "bp";
piecePositions[1][6] = "bp";
piecePositions[1][7] = "bp";
piecePositions[0][1] = "bn";
piecePositions[0][6] = "bn";
piecePositions[0][2] = "bb";
piecePositions[0][5] = "bb";
piecePositions[0][0] = "br";
piecePositions[0][7] = "br";
piecePositions[0][3] = "bq";
piecePositions[0][4] = "bk";
System.out.println(printChessBoard(piecePositions));
for (int row = 0; row < boardTiles.length; row++) {
for (int col = 0; col < boardTiles[row].length; col++) {
boardTiles[row][col] = new JPanel() {
private static final long serialVersionUID = 1L;
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
};
if (row % 2 == 0) {
if (col % 2 == 0) {
boardTiles[row][col].setBackground(new Color(240, 217, 181)); // light
// brown
} else if (col % 2 != 0) {
boardTiles[row][col].setBackground(new Color(181, 136, 99)); // dark
// brown
}
} else if (row % 2 != 0) {
if (col % 2 != 0) {
boardTiles[row][col].setBackground(new Color(240, 217, 181)); // light
// brown
} else if (col % 2 == 0) {
boardTiles[row][col].setBackground(new Color(181, 136, 99)); // dark
// brown
}
}
boardTiles[row][col].setLayout(new BorderLayout());
final int tempRow = row;
final int tempCol = col;
boardTiles[row][col].addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
System.out.println("row : " + tempRow + ", col: " + tempCol);
if (piecePositions[tempRow][tempCol] == "wp") {
System.out.println("White pawn");
lastSelected = "wp";
} else if (piecePositions[tempRow][tempCol] == "wn") {
System.out.println("White knight");
lastSelected = "wn";
} else if (piecePositions[tempRow][tempCol] == "wb") {
System.out.println("White bishop");
lastSelected = "wb";
} else if (piecePositions[tempRow][tempCol] == "wr") {
System.out.println("White rook");
lastSelected = "wr";
} else if (piecePositions[tempRow][tempCol] == "wq") {
System.out.println("White queen");
lastSelected = "wq";
} else if (piecePositions[tempRow][tempCol] == "wk") {
System.out.println("White king");
lastSelected = "wk";
} else if (piecePositions[tempRow][tempCol] == "bp") {
System.out.println("Black pawn");
lastSelected = "bp";
} else if (piecePositions[tempRow][tempCol] == "bn") {
System.out.println("Black knight");
lastSelected = "bn";
} else if (piecePositions[tempRow][tempCol] == "bb") {
System.out.println("Black bishop");
lastSelected = "bb";
} else if (piecePositions[tempRow][tempCol] == "br") {
System.out.println("Black rook");
lastSelected = "br";
} else if (piecePositions[tempRow][tempCol] == "bq") {
System.out.println("Black queen");
lastSelected = "bq";
} else if (piecePositions[tempRow][tempCol] == "bk") {
System.out.println("Black king");
lastSelected = "bk";
} else {
System.out.println("Blank tile");
if (lastSelected != null) {
piecePositions[lastSelectedRow][lastSelectedCol] = null;
piecePositions[tempRow][tempCol] = lastSelected;
}
}
lastSelectedRow = tempRow;
lastSelectedCol = tempCol;
System.out.println(printChessBoard(piecePositions));
boardTiles[tempRow][tempCol].setBackground(new Color(255, 255, 255, 127));
boardTiles[tempRow][tempCol].repaint();
}
});
JLabel piecePicLabel = new JLabel();
if (piecePositions[row][col] == "wp") {
piecePicLabel = new JLabel(new ImageIcon(whitePawnGUI));
} else if (piecePositions[row][col] == "wn") {
piecePicLabel = new JLabel(new ImageIcon(whiteKnightGUI));
} else if (piecePositions[row][col] == "wb") {
piecePicLabel = new JLabel(new ImageIcon(whiteBishopGUI));
} else if (piecePositions[row][col] == "wr") {
piecePicLabel = new JLabel(new ImageIcon(whiteRookGUI));
} else if (piecePositions[row][col] == "wq") {
piecePicLabel = new JLabel(new ImageIcon(whiteQueenGUI));
} else if (piecePositions[row][col] == "wk") {
piecePicLabel = new JLabel(new ImageIcon(whiteKingGUI));
} else if (piecePositions[row][col] == "bp") {
piecePicLabel = new JLabel(new ImageIcon(blackPawnGUI));
} else if (piecePositions[row][col] == "bn") {
piecePicLabel = new JLabel(new ImageIcon(blackKnightGUI));
} else if (piecePositions[row][col] == "bb") {
piecePicLabel = new JLabel(new ImageIcon(blackBishopGUI));
} else if (piecePositions[row][col] == "br") {
piecePicLabel = new JLabel(new ImageIcon(blackRookGUI));
} else if (piecePositions[row][col] == "bq") {
piecePicLabel = new JLabel(new ImageIcon(blackQueenGUI));
} else if (piecePositions[row][col] == "bk") {
piecePicLabel = new JLabel(new ImageIcon(blackKingGUI));
}
boardTiles[row][col].add(piecePicLabel);
boardTiles[row][col].repaint();
}
}
JPanel basePanel = new JPanel() {
private static final long serialVersionUID = 1L;
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// draw the board
g2d.drawRect(26, 0, 624, 624);
for (int i = 0; i < 8; i++) {
// numbers and letters labels
g2d.setColor(Color.white);
g2d.drawString("12345678".substring(i, i + 1), 10, i * 78 + 39);
g2d.drawString("abcdefgh".substring(i, i + 1), i * 78 + 39 + 20, 640);
}
}
};
basePanel.setBackground(Color.black);
basePanel.setLayout(new GridLayout(8, 8));
basePanel.setPreferredSize(new Dimension(650, 650));
for (int row = 0; row < boardTiles.length; row++) {
for (int col = 0; col < boardTiles.length; col++) {
basePanel.add(boardTiles[row][col]);
}
}
getContentPane().add(basePanel);
pack();
setLocationRelativeTo(null);
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
new Chess();
} catch (IOException ex) {
ex.printStackTrace();
}
}
});
}
这是输出的图片:
棋盘上的64个棋子每一个都是一个JPanel，棋子的图像都放在每个JPanel中。正如你所看到的，当我尝试移动 pawn 时，它在矩阵中移动，但不在 GUI 中移动。我该如何解决这个问题？
最佳答案
当您在矩阵内执行移动时，您实际上并未在图形板内执行移动 (JPanel[][])。
所以除其他外:
// ...
} else {
System.out.println("Blank tile");
if (lastSelected != null) {
piecePositions[lastSelectedRow][lastSelectedCol] = null;
piecePositions[tempRow][tempCol] = lastSelected;
//
// HERE you miss something I guess <<<<<<<<<<<<<<<<<<<<<
// Do something with boardTiles...
}
}
// ...
还有一点很重要:在比较字符串时切勿使用 == 或 != ，否则您可能会遇到麻烦(将是恶性的)。相反，如果您害怕 null，请使用以下结构:
if("bn".equals(piecePositions[row][col])) {
// you avoid NullPointerException that way
}
更重要的是，我们假设这是一些沙箱代码..否则它缺少很多东西:
- 进行面向对象编程。至少定义
Board、Piece和Move类。它会让你的生活变得如此美好。 - 同时尝试能够区分 GUI 代码和纯代码。您可以通过这种方式轻松调试您的应用，并且通常它必须可以在单元测试中进行测试，并且可以毫不费力地使用控制台输入/输出。
- 清理你的代码，创建方法，快乐起来。
关于Java Chess，如何更新棋盘？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47230274/