java - 如何在 GroupLayout Java 中设置 Jframe 背景图像

Question

我正在尝试为我的框架设置背景图像，但它不起作用。我试过这个链接：

在 JFrame 中设置背景图像

编码：

setContentPane(new JLabel(new ImageIcon(ImageIO.read(new File("/Images/about.png")))));

我尝试将上面的代码添加到我的 Contentpane 但它不起作用。

public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                MainMenu frame = new MainMenu();
                frame.setVisible(true);

            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

/**
 * Create the frame.
 */
public MainMenu() {
    setIconImage(Toolkit.getDefaultToolkit().getImage(MainMenu.class.getResource("/Images/bug-red.png")));
    setTitle("Automated Bug Fixing");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 712, 458);

            contentPane = new JPanel();

    //contentPane.setBackground(new Color(220, 220, 220));
    contentPane.setForeground(new Color(32, 178, 170));
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
            *setContentPane(new JLabel(new ImageIcon(ImageIO.read(new File("/Images/about.png")))));*

Answer 1

基本概念看起来不错。

您遇到问题的唯一可能原因是图像不存在。

看起来您正在尝试引用应该存在于 Jar 上下文中的图像

代替

ImageIO.read(new File("/Images/about.png"))

尝试

ImageIO.read(getClass().getResource("/Images/about.png"))

反而。

另外，不要吞下异常，确保至少记录所有异常

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.HeadlessException;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class BackgroundFrameImage {

    public static void main(String[] args) {
        new BackgroundFrameImage();
    }

    public BackgroundFrameImage() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                try {
                    JLabel label = new JLabel(new ImageIcon(ImageIO.read(...))));

                    JFrame frame = new JFrame("Testing");
                    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    frame.setContentPane(label);
                    frame.setLayout(new BorderLayout());
                    JLabel text = new JLabel("Hello from the foreground");
                    text.setForeground(Color.WHITE);
                    text.setHorizontalAlignment(JLabel.CENTER);
                    frame.add(text);
                    frame.pack();
                    frame.setLocationRelativeTo(null);
                    frame.setVisible(true);
                } catch (IOException | HeadlessException exp) {
                    exp.printStackTrace();
                }
            }
        });
    }

}

Answer 2

我知道问题可能出在

setContentPane(new JLabel(new ImageIcon(ImageIO.read(new File("/Images/about.png")))));

尝试删除文件路径中的前导斜杠，因为这可能会因操作系统而异：

setContentPane(new JLabel(new ImageIcon(ImageIO.read(new File("Images/about.png")))));

Answer 3

将所有内容放在IPanel 上，并将IPanel 放在JFrame 上。根据需要进行调整以满足您的需求。

public class IPanel extends JPanel {
private static final long serialVersionUID = 1L;
private Image             imageOrg         = null;
private Image             image            = null;
{
    addComponentListener(new ComponentAdapter() {
        @Override
        public void componentResized(final ComponentEvent e) {
            final int w = IPanel.this.getWidth();
            final int h = IPanel.this.getHeight();
            image = w > 0 && h > 0 ? imageOrg.getScaledInstance(w, h, Image.SCALE_SMOOTH) : imageOrg;
            IPanel.this.repaint();
        }
    });
}

public IPanel(final Image i) {
    imageOrg = i;
    image = i;
}

@Override
public void paintComponent(final Graphics g) {
    super.paintComponent(g);
    if (image != null)
        g.drawImage(image, 0, 0, null);
}
}

例子：

    final JPanel j = new IPanel(image);
    j.setLayout(new FlowLayout());
    j.add(new JButton("YoYo"));
    j.add(new JButton("MaMa"));
    j.add(new JLabel(icon));

产生：