【发布时间】：2013-06-05 00:07:13
【问题描述】：
我正在开发一个程序，以使用 swing gui 在 Java 中生成和解决数独难题。我在 JTextField 上使用 .setText() 方法但文本未更新时遇到问题。
这是我的代码：
主类：
package sudoku;
public class SudokuSolver {
public static void main(String[] args) {
GUI gui = new GUI();
gui.setVisible(true);
}
}
GUI类：
package sudoku;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JButton;
import java.awt.Window.Type;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class GUI extends JFrame implements ActionListener {
private JPanel contentPane;
private Puzzle puzzle = new Puzzle();
private Board board = new Board();
private int[][] puzz = new int[9][9];
// GUI Constructor
public GUI() {
// set up window
setResizable(false);
setTitle("Sudoku Solver");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 300, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
// set up button panel
JPanel buttons = new JPanel();
contentPane.add(buttons, BorderLayout.SOUTH);
// set up generate button
JButton genButton = new JButton("Generate");
genButton.setMnemonic('g');
buttons.add(genButton);
genButton.addActionListener(this);
// set up solve button
JButton solveButton = new JButton("Solve");
solveButton.setMnemonic('s');
buttons.add(solveButton);
solveButton.addActionListener(this);
// set up board
contentPane.add(board, BorderLayout.CENTER);
}
// Button listener
public void actionPerformed(ActionEvent e) {
String cmd = e.getActionCommand();
if (cmd == "Generate") {
// generate puzzle
puzz = puzzle.generate();
} else if (cmd == "Solve") {
// solve puzzle
puzz = puzzle.solve(puzz);
}
// display puzzle on the board
board.fill(puzz);
}
}
板级：
package sudoku;
import java.awt.Color;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JPanel;
public class Board extends JPanel {
// 9x9 board sections
private BoardSection nw = new BoardSection();
private BoardSection n = new BoardSection();
private BoardSection ne = new BoardSection();
private BoardSection w = new BoardSection();
private BoardSection c = new BoardSection();
private BoardSection e = new BoardSection();
private BoardSection sw = new BoardSection();
private BoardSection s = new BoardSection();
private BoardSection se = new BoardSection();
// array of sections
private BoardSection[] sections = { nw, n, ne, w, c, e, sw, s, se };
// Board Constructor
public Board() {
// 3x3 grid layout
setLayout(new GridLayout(3, 3));
// border
setBorder(BorderFactory.createLineBorder(Color.BLACK, 2));
// add board sections to board
for (int i = 0; i < sections.length; i++) {
sections[i] = new BoardSection();
add(sections[i]);
}
}
// fill the board with data
public void fill(int[][] data) {
// create data sections
String[][] nwData = new String[3][3];
String[][] nData = new String[3][3];
String[][] neData = new String[3][3];
String[][] wData = new String[3][3];
String[][] cData = new String[3][3];
String[][] eData = new String[3][3];
String[][] swData = new String[3][3];
String[][] sData = new String[3][3];
String[][] seData = new String[3][3];
// break data into data sections
nwData = createSection(data, 0, 0);
nData = createSection(data, 3, 0);
neData = createSection(data, 6, 0);
wData = createSection(data, 0, 3);
cData = createSection(data, 3, 3);
eData = createSection(data, 6, 3);
swData = createSection(data, 0, 6);
sData = createSection(data, 3, 6);
seData = createSection(data, 6, 6);
// fill board section with data section
nw.fillSection(nwData);
n.fillSection(nData);
ne.fillSection(neData);
w.fillSection(wData);
c.fillSection(cData);
e.fillSection(eData);
sw.fillSection(swData);
s.fillSection(sData);
se.fillSection(seData);
}
// split data into 3x3 section with 0,0 starting at x, y then convert to
// string
private String[][] createSection(int[][] data, int x, int y) {
int[][] intSection = new int[3][3];
String[][] strSection = new String[3][3];
// break into section
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
intSection[i][j] = data[i + x][j + y];
}
}
// convert section to string
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
strSection[i][j] = Integer.toString(intSection[i][j]);
}
}
return strSection;
}
}
BoardSection 类：
package sudoku;
import java.awt.Color;
import java.awt.GridLayout;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.BorderFactory;
public class BoardSection extends JPanel {
// each square
private JTextField nw = new JTextField();
private JTextField n = new JTextField();
private JTextField ne = new JTextField();
private JTextField w = new JTextField();
private JTextField c = new JTextField();
private JTextField e = new JTextField();
private JTextField sw = new JTextField();
private JTextField s = new JTextField();
private JTextField se = new JTextField();
// array of the squares
private JTextField[] fields = new JTextField[] { nw, n, ne, w, c, e, sw, s,
se };
// Board Section Constructor
public BoardSection() {
// 3x3 grid layout
setLayout(new GridLayout(3, 3));
// border
setBorder(BorderFactory.createLineBorder(Color.BLACK, 1));
// add all fields to the board section
for (int i = 0; i < fields.length; i++) {
fields[i] = new JTextField(1);
fields[i].setHorizontalAlignment(JTextField.CENTER);
fields[i].setEditable(false);
add(fields[i]);
}
}
// Display the data on the board
public void fillSection(String[][] data) {
int x = 0;
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
fields[x].setText(data[i][j]);
x++;
}
}
}
}
我还有另一个名为 Puzzle 的类，其中有一个 generate() 和一个 solve() 方法，它们都返回 int[][]。我不相信其中的任何内容与问题有关，因此我将其省略。
问题在于这一行是 BoardSection 类：
fields[x].setText(data[i][j]);
我没有收到任何错误消息，但它没有更新文本。我尝试用“Z”替换 data[i][j] 以查看问题是否出在我传递的数据上，但它仍然不适用于仅使用一个简单的字符串。但是，我确实尝试将以下行放在 BoardSection 构造函数方法内部的 for 循环中，并且它确实显示了。
fields[i].setText("0");
谁能解释为什么它在构造函数中起作用，但在调用 fillSection() 方法时不起作用？
【问题讨论】：
-
我建议您在程序运行时启动调试器来查看代码中变量的值。
标签： java swing user-interface jtextfield