第一张图片显示了我刚启动时 GUI 的样子，第二张图片显示了当我在板上单击时发生的情况。在我单击棋子然后单击顶行的按钮后，棋子出现在顶行。这里发生了什么？!
代码如下；这个类是我拥有大部分代码的地方。其余的类此时只是加载图像。主要调用 Board 构造函数来构建 GUI。
public class BoardPanel extends JPanel {
public BoardPanel() {
createBoard();
}
private void createBoard(){
setLayout(new GridLayout(10, 10));
// Makes a 10 x 10 grid of black and white colors
for (int i = 0; i<10; i++){
for (int j = 0; j<10; j++){
square[i][j] = new JButton();
square[i][j].setRolloverEnabled(false);
if ((i+j)%2 == 0)
square[i][j].setBackground(Color.WHITE);
else
square[i][j].setBackground(Color.LIGHT_GRAY);
add(square[i][j]);
}
}
addLabels();
//Colors the corner squares
square[0][0].setBackground(new Color(155, 234, 242, 100));
square[0][9].setBackground(new Color(155, 234, 242, 100));
square[9][0].setBackground(new Color(155, 234, 242, 100));
square[9][9].setBackground(new Color(155, 234, 242, 100));
}
private void addLabels(){
//Adds labels to the ranks
for (int i =1 ; i< 9; i++){
square[i][0].setBackground(new Color(155, 234, 242, 100));
square[i][0].setText(rank[8-i]);
square[i][0].setHorizontalTextPosition(SwingConstants.RIGHT);
square[i][9].setBackground(new Color(155, 234, 242, 100));
square[i][9].setText(rank[8-i]);
square[i][9].setHorizontalTextPosition(SwingConstants.LEFT);
}
//Adds labels to the files
for (int j = 1; j<9;j++){
square[0][j].setBackground(new Color(155, 234, 242, 100));
square[0][j].setText(file[j-1]);
square[0][j].setVerticalTextPosition(SwingConstants.BOTTOM);
square[9][j].setBackground(new Color(155, 234, 242, 100));
square[9][j].setText(file[j-1]);
square[9][j].setVerticalTextPosition(SwingConstants.TOP);
}
JButton square[][] = new JButton[10][10];
String[] rank = {"1","2","3","4","5","6","7","8"};
String[] file = {"a","b","c","d","e","f","g","h"};
}
}
主类
public class Board {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.add(new BoardPanel());
frame.setVisible(true);
frame.setSize(900, 700);
}
}
请您参考如下方法:
你的问题是按钮认为它是完全不透明的，而实际上它不是不透明的。根据 Kleopatra 在 this answer ，您必须使按钮不透明并接管绘画机制
square[i][j] = new JButton() {
@Override // !! add this:
protected void paintComponent(Graphics g) {
if (!isOpaque() && getBackground().getAlpha() < 255) {
g.setColor(getBackground());
g.fillRect(0, 0, getWidth(), getHeight());
}
super.paintComponent(g);
}
};
square[i][j].setRolloverEnabled(false);
square[i][j].setOpaque(false); // !! and also add this *******
作为旁注，我不会使用 JButtons 来解决此类问题，而是使用 JPanels，并将我的棋子作为 ImageIcons 显示在 JLabels 中，添加到或从中删除的标签适当的棋盘方 block 。
没有按钮且没有使用 alpha 颜色的面板:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import javax.swing.*;
@SuppressWarnings("serial")
public class Board2 extends JPanel {
private static final int SIDE_LEN = 80;
private static final Dimension SQUARE_SZ = new Dimension(SIDE_LEN, SIDE_LEN);
private static final Color EDGE_COLOR = new Color(165, 245, 250);
private static final Color DARK_SQR_COLOR = Color.LIGHT_GRAY;
private static final Color LIGHT_SQR_COLOR = Color.WHITE;
private JPanel[][] chessSquares = new JPanel[8][8];
public Board2() {
setLayout(new GridLayout(10, 10)); // sorry for magic numbers
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
if ((i == 0 || i == 9) && (j == 0 || j == 9)) {
add(createEdgePanel(""));
} else if (i == 0 || i == 9) {
String text = String.valueOf((char) (j + 'a' - 1));
add(createEdgePanel(text));
} else if (j == 0 || j == 9) {
String text = String.valueOf(8 - i + 1);
add(createEdgePanel(text));
} else {
JPanel panel = createSquare(i, j);
add(panel);
}
}
}
}
private JPanel createSquare(int i, int j) {
JPanel panel = new JPanel(new GridBagLayout());
Color c = (i % 2 == j % 2) ? LIGHT_SQR_COLOR : DARK_SQR_COLOR;
panel.setBackground(c);
panel.setPreferredSize(SQUARE_SZ);
panel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
return panel;
}
private JPanel createEdgePanel(String text) {
JLabel label = new JLabel(text, SwingConstants.CENTER);
JPanel panel = new JPanel(new GridBagLayout());
panel.add(label);
panel.setBackground(EDGE_COLOR);
panel.setPreferredSize(SQUARE_SZ);
panel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
return panel;
}
private static void createAndShowGui() {
Board2 mainPanel = new Board2();
JFrame frame = new JFrame("Board2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
在我的系统上看起来像:
现在添加了一些片段:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.*;
@SuppressWarnings("serial")
public class Board2 extends JPanel {
private static final int SIDE_LEN = 80;
private static final Dimension SQUARE_SZ = new Dimension(SIDE_LEN, SIDE_LEN);
private static final String SPRITE_PATH = "http://i.stack.imgur.com/memI0.png";
private static final int SPRITE_ROWS = 2;
private static final int SPRITE_COLS = 6;
private static final Color EDGE_COLOR = new Color(165, 245, 250);
private static final Color DARK_SQR_COLOR = Color.LIGHT_GRAY;
private static final Color LIGHT_SQR_COLOR = Color.WHITE;
private static final int ROWS = 8;
private JLabel[][] chessSquares = new JLabel[ROWS][ROWS];
private BufferedImage bigImage;
private List<Icon> icons = new ArrayList<>();
public Board2() throws IOException {
URL imgUrl = new URL(SPRITE_PATH);
bigImage = ImageIO.read(imgUrl);
int w = bigImage.getWidth() / SPRITE_COLS;
int h = bigImage.getHeight() / SPRITE_ROWS;
for (int i = 0; i < SPRITE_ROWS; i++) {
for (int j = 0; j < SPRITE_COLS; j++) {
int x = (j * bigImage.getWidth()) / SPRITE_COLS;
int y = (i * bigImage.getHeight()) / SPRITE_ROWS;
BufferedImage spriteImg = bigImage.getSubimage(x, y, w, h);
Icon spriteIcon = new ImageIcon(spriteImg);
icons.add(spriteIcon);
}
}
for (int i = 0; i < chessSquares.length; i++) {
for (int j = 0; j < chessSquares[i].length; j++) {
chessSquares[i][j] = new JLabel();
}
}
setLayout(new GridLayout(ROWS + 2, ROWS + 2)); // sorry for magic numbers
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
if ((i == 0 || i == ROWS + 1) && (j == 0 || j == ROWS + 1)) {
add(createEdgePanel(""));
} else if (i == 0 || i == ROWS + 1) {
String text = String.valueOf((char) (j + 'a' - 1));
add(createEdgePanel(text));
} else if (j == 0 || j == ROWS + 1) {
String text = String.valueOf(ROWS - i + 1);
add(createEdgePanel(text));
} else {
JPanel panel = createSquare(i, j);
panel.add(chessSquares[i - 1][j - 1]);
add(panel);
}
}
}
setPieces(0, 0, 2); // rooks
setPieces(1, 0, 3); // knights
setPieces(2, 0, 4); // bishops
// kings and queens
chessSquares[0][3].setIcon(icons.get(1));
chessSquares[7][3].setIcon(icons.get(6 + 1));
chessSquares[0][4].setIcon(icons.get(0));
chessSquares[7][4].setIcon(icons.get(6 + 0));
// pawns
for (int i = 0; i < ROWS / 2; i++) {
setPieces(i, 1, 5);
}
}
private void setPieces(int colPos, int rowPos, int pieceIndex) {
chessSquares[rowPos][colPos].setIcon(icons.get(pieceIndex));
chessSquares[rowPos][ROWS - 1 - colPos].setIcon(icons.get(pieceIndex));
chessSquares[ROWS - 1 - rowPos][colPos].setIcon(icons.get(6 + pieceIndex));
chessSquares[ROWS - 1 - rowPos][ROWS - 1 - colPos].setIcon(icons
.get(6 + pieceIndex));
}
private void setPiece(int colPos, int pieceIndex) {
chessSquares[0][colPos].setIcon(icons.get(pieceIndex));
chessSquares[ROWS - 1][ROWS - 1 - colPos].setIcon(icons.get(6 + pieceIndex));
}
private JPanel createSquare(int i, int j) {
JPanel panel = new JPanel(new GridBagLayout());
Color c = (i % 2 == j % 2) ? LIGHT_SQR_COLOR : DARK_SQR_COLOR;
panel.setBackground(c);
panel.setPreferredSize(SQUARE_SZ);
panel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
return panel;
}
private JPanel createEdgePanel(String text) {
JLabel label = new JLabel(text, SwingConstants.CENTER);
JPanel panel = new JPanel(new GridBagLayout());
panel.add(label);
panel.setBackground(EDGE_COLOR);
panel.setPreferredSize(SQUARE_SZ);
panel.setBorder(BorderFactory.createLineBorder(Color.GRAY));
return panel;
}
private static void createAndShowGui() {
Board2 mainPanel = null;
try {
mainPanel = new Board2();
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
JFrame frame = new JFrame("Board2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
