我试图在JPanel顶部放置一个.jpg图标，以便在板上表示一块木板。我有一个包含.java文件的GUI文件夹和另一个包含.jpg文件的文件夹。
-主要编辑-
范例程式码
单击一个正方形时，应放置一个白色图标，然后放置一个黑色图标，等等。这是我试图实现的非常基本的示例
import java.awt.Dimension;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class gui extends JFrame implements MouseListener {
/**
*
*/
private static final long serialVersionUID = -973341728129968945L;
JLayeredPane layeredPane;
JPanel board;
JLabel piece;
int numSquares;
private boolean currentPlayer;
public gui(){
Dimension boardSize = new Dimension(600, 600);
numSquares = 6;
currentPlayer = true;
layeredPane = new JLayeredPane();
getContentPane().add(layeredPane);
layeredPane.setPreferredSize(boardSize);
layeredPane.addMouseListener(this);
board = new JPanel();
layeredPane.add(board, JLayeredPane.DEFAULT_LAYER);
board.setLayout( new GridLayout(numSquares, numSquares) );
board.setPreferredSize( boardSize );
board.setBounds(0, 0, boardSize.width, boardSize.height);
for (int i = 0; i < (numSquares * numSquares); i++) {
JPanel square = new JPanel( new BorderLayout() );
square.setBorder(BorderFactory.createLineBorder(Color.black));
square.setBackground(Color.green);
board.add( square );
}
}
public static void main(String[] args) {
JFrame frame = new gui();
frame.setDefaultCloseOperation(DISPOSE_ON_CLOSE );
frame.pack();
frame.setResizable(true);
frame.setLocationRelativeTo( null );
frame.setVisible(true);
}
@Override
public void mouseClicked(MouseEvent e) {
JPanel temp = (JPanel)board.findComponentAt(e.getX(), e.getY());
System.out.println(e.getX() + " " + e.getY());
if( currentPlayer ){
ImageIcon white = new ImageIcon("l/Images/white.jpg");
piece = new JLabel(white);
temp.add(piece);
}
else{
ImageIcon black = new ImageIcon( "/Images/black.jpg");
piece = new JLabel(black);
temp.add(piece);
}
currentPlayer = !currentPlayer;
}
@Override
public void mouseEntered(MouseEvent e) {
}
@Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void mouseReleased(MouseEvent e) {
}
}
最佳答案
如果要从容器中添加或删除组件，请不要忘记重新验证和重新绘制。我已经修改了您的SSCCE，并且摆脱了使用图像的麻烦，使那些无法访问您的图像文件的人（例如我！）可以运行它。更改通过// !!注释记录：
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
public class Gui2 extends JFrame implements MouseListener {
private static final long serialVersionUID = -973341728129968945L;
JLayeredPane layeredPane;
JPanel board;
JLabel piece;
int numSquares;
private boolean currentPlayer;
// !!
private ImageIcon whiteIcon;
private ImageIcon blackIcon;
public Gui2() {
// !!
whiteIcon = createIcon(Color.white);
blackIcon = createIcon(Color.black);
Dimension boardSize = new Dimension(600, 600);
numSquares = 6;
currentPlayer = true;
layeredPane = new JLayeredPane();
getContentPane().add(layeredPane);
layeredPane.setPreferredSize(boardSize);
layeredPane.addMouseListener(this);
board = new JPanel();
layeredPane.add(board, JLayeredPane.DEFAULT_LAYER);
board.setLayout(new GridLayout(numSquares, numSquares));
board.setPreferredSize(boardSize);
board.setBounds(0, 0, boardSize.width, boardSize.height);
for (int i = 0; i < (numSquares * numSquares); i++) {
// !! JPanel square = new JPanel(new BorderLayout());
JPanel square = new JPanel(new GridBagLayout()); // !!
square.setBorder(BorderFactory.createLineBorder(Color.black));
square.setBackground(Color.green);
square.setName(String.format("[%d, %d]", i % numSquares, i
/ numSquares)); // !!
board.add(square);
}
}
// !!
private ImageIcon createIcon(Color color) {
int width = 40;
int height = width;
BufferedImage img = new BufferedImage(width, height,
BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(color);
g2.fillOval(0, 0, width, height);
g2.dispose();
ImageIcon icon = new ImageIcon(img);
return icon;
}
public static void main(String[] args) {
JFrame frame = new Gui2();
frame.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
frame.pack();
frame.setResizable(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
@Override
// !!
public void mousePressed(MouseEvent e) {
JPanel temp = (JPanel) board.findComponentAt(e.getX(), e.getY());
System.out.println(e.getX() + " " + e.getY());
System.out.println(temp.getName()); // !!
if (currentPlayer) {
// !! ImageIcon white = new ImageIcon("l/Images/white.jpg");
// !! piece = new JLabel(white);
piece = new JLabel(whiteIcon); // !!
temp.add(piece);
} else {
// !! ImageIcon black = new ImageIcon("/Images/black.jpg");
// !! piece = new JLabel(black);
piece = new JLabel(blackIcon); // !!
temp.add(piece);
}
temp.revalidate(); // !!
temp.repaint(); // !!
currentPlayer = !currentPlayer;
}
@Override
public void mouseEntered(MouseEvent e) {
}
@Override
public void mouseExited(MouseEvent arg0) {
}
@Override
public void mouseClicked(MouseEvent arg0) {
}
@Override
public void mouseReleased(MouseEvent e) {
}
}
同样，类名也应大写，并且您应该再次制作一次ImageIcons。同样，一个ImageIcon可以由许多JLabel共享。您还需要响应mousePressed而不是mouseClicked，因为mouseClicked可能很挑剔，特别是如果您在按下和释放鼠标之间移动了鼠标。
希望您也已经看到了SSCCE的价值。 :)