我有一个图像，我想要的是将此图像打包到JLabel中并将其添加到我的JLayeredPane以稍后对多个图像进行分层。 它使用一个没有JLayeredPane的Image，但是当使用JLayeredPane时我只能看到我的边框。 我必须对多个图像进行分层，以便ypu可以配置比萨并查看您的自定义比萨饼。
package view;
import javax.swing.*;
import java.awt.*;
/**
* ImagePanel used to scale and display an image
*/
public class ImagePanel extends JPanel {
private JLayeredPane layeredPane;
/**
* Setup an ImagePanel, get the image, scale it and set it as a label to display it
*/
public ImagePanel(){
layeredPane = new JLayeredPane();
layeredPane.setPreferredSize(new Dimension(300, 300));
layeredPane.setBorder(BorderFactory.createTitledBorder("Your Pizza"));
ImageIcon icon = new ImageIcon(getClass().getResource("/images/pizzaboden.png"));
JLabel imgLabel = new JLabel(icon);
layeredPane.add(imgLabel);
add(layeredPane);
}
}
阅读图像是有效的，这是我之前阅读它的方式，它运行良好：
我的数据字段
private ImageIcon imageIcon;
private ImageIcon scaledImageIcon;
private JLabel imageLabel;
private Image image;
private Image scaledImage;
我的构造函数
imageIcon = new ImageIcon(getClass().getResource("/images/pizzaboden.png"));
image = imageIcon.getImage();
scaledImage = image.getScaledInstance(280, 280, Image.SCALE_SMOOTH);
scaledImageIcon = new ImageIcon(scaledImage);
imageLabel = new JLabel(scaledImageIcon);
add(imageLabel);
答案 0 :(得分：1)
当您向JLayeredPane添加内容时，您需要根据JLayeredPane tutorial指定在X / Y维度中添加组件的位置以及分层维度中的位置，并且您不需要＆＃39这样做。您还需要为JLabel提供一个大小，因为JLayeredPane不会考虑它的首选大小。像
这样的东西
imgLabel.setSize(imgLabel.getPreferredSize());
imgLabel.setPosition(0, 0);
layeredPane.add(imgLabel, JLayeredPane.DEFAULT_LAYER);
可能就足够了。
另外，您是否独立于当前程序进行了测试，以确保正确读取图像？此外，您使用JPanel添加到FlowLayout - 您确定要执行此操作吗？也许最好是给你的ImagePanel一个BorderLayout。
请注意，如果我在做这样的事情，在Swing GUI中显示多个重叠图像，我就不会使用JLayeredPane，而是在单个paintComponent(Graphics g)方法中绘制图像（BufferedImages）绘制JPanel，并在需要时从GUI添加和删除图像，然后在绘图JPanel上调用repaint()。
例如，如果你给绘图JPanel一个像这样的图像的ArrayList：
private List<Image> images = new ArrayList<>();
您可以通过遍历paintComponent方法中的列表来绘制此列表所包含的任何图像：
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Image image : images) {
g.drawImage(image, 0, 0, this);
}
}
您可以轻松添加和删除图像：
public void clearImages() {
images.clear();
repaint();
}
public void removeImage(Image image) {
images.remove(image);
repaint();
}
public void addImage(Image image) {
images.add(image);
repaint();
}
例如，这里是您可以运行的概念验证代码，它演示了我的意思：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.imageio.ImageIO;
import javax.swing.*;
public class MultipleImages extends JPanel {
private static final String BULLS_EYE_PATH = "https://upload.wikimedia.org/wikipedia/"
+ "commons/thumb/3/36/Roundel_of_the_Serbian_Air_Force_1915.svg/"
+ "300px-Roundel_of_the_Serbian_Air_Force_1915.svg.png";
private static final String CHINESE_CHAR_PATH = "https://upload.wikimedia.org/"
+ "wikipedia/commons/1/1a/%E9%9D%91-red.png";
private static final String HOCKY_PATH = "https://upload.wikimedia.org/wikipedia/"
+ "commons/thumb/e/eb/Ice_hockey_pictogram.svg/"
+ "300px-Ice_hockey_pictogram.svg.png";
private static final String[] LABELS = {"Bulls Eye", "Chinese Character", "Hockey"};
private static final String[] IMAGE_PATHS = {BULLS_EYE_PATH, CHINESE_CHAR_PATH, HOCKY_PATH};
private Map<String, Image> imageMap = new HashMap<>();
private List<JCheckBox> checkBoxes = new ArrayList<>();
private ImagePanel imagePanel = new ImagePanel();
public MultipleImages() throws IOException {
for (int i = 0; i < IMAGE_PATHS.length; i++) {
URL imgUrl = new URL(IMAGE_PATHS[i]);
BufferedImage img = ImageIO.read(imgUrl);
imageMap.put(LABELS[i], img);
}
ActionListener checkBoxListener = e -> {
imagePanel.clearImages();
for (JCheckBox checkBox : checkBoxes) {
if (checkBox.isSelected()) {
String label = checkBox.getActionCommand();
imagePanel.addImage(imageMap.get(label));
}
}
imagePanel.repaint();
};
JPanel checkBoxPanel = new JPanel(new GridLayout(0, 1));
for (String label : LABELS) {
JCheckBox checkBox = new JCheckBox(label);
checkBox.setActionCommand(label);
checkBoxes.add(checkBox);
checkBoxPanel.add(checkBox);
checkBox.addActionListener(checkBoxListener);
}
JPanel rightPanel = new JPanel(new BorderLayout());
rightPanel.add(checkBoxPanel, BorderLayout.PAGE_START);
setLayout(new BorderLayout());
add(rightPanel, BorderLayout.LINE_START);
add(imagePanel);
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Multiple Images");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try {
frame.getContentPane().add(new MultipleImages());
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
public class ImagePanel extends JPanel {
private static final int PREF_W = 300;
private static final int PREF_H = PREF_W;
private static final Color BACKGROUND = Color.WHITE;
private List<Image> images = new ArrayList<>();
public ImagePanel() {
setBackground(BACKGROUND);
setBorder(BorderFactory.createLineBorder(Color.BLACK));
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Image image : images) {
g.drawImage(image, 0, 0, this);
}
}
public void clearImages() {
images.clear();
repaint();
}
public void removeImage(Image image) {
images.remove(image);
repaint();
}
public void addImage(Image image) {
images.add(image);
repaint();
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
}