嵌套JPanel中的背景图像？

我有一个JPanel，其中包含2个JPanel。 位于左侧（左侧框）和右侧（rB），我想在右侧JPanel（rB）上添加背景图像。

但我得到的结果是

http://sofzh.miximages.com/java/tHz1x.jpg

我想要的结果

http://sofzh.miximages.com/java/xHbpx.jpg

public void paintComponent(Graphics g) { //this.paintComponent(g); if(wdimage != null) g.drawImage(wdimage,0,0,800,800,rB); //(image,location x, location y, size x, size y) } 

rB Panel正在阻止图像，我想要的是在JPanel上显示图像，并在JPanel上添加一些jlabels和文本字段，稍后再添加图像。

Answer 1

这里出现没有任何问题，看看：

 import java.awt.*; import java.awt.image.BufferedImage; import java.net.URL; import javax.imageio.ImageIO; import javax.swing.*; public class PanelExample { private void createAndDisplayGUI() { JFrame frame = new JFrame("Panel Example"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel contentPane = new JPanel(); contentPane.setOpaque(true); contentPane.setBorder( BorderFactory.createMatteBorder( 5, 5, 5, 5, Color.WHITE)); contentPane.setBackground(Color.WHITE); contentPane.setLayout(new BorderLayout(10, 10)); ImagePanel imagePanel = new ImagePanel(); //imagePanel.createGUI(); BlankPanel blankPanel = new BlankPanel(); contentPane.add(blankPanel, BorderLayout.LINE_START); contentPane.add(imagePanel, BorderLayout.CENTER); frame.setContentPane(contentPane); frame.pack(); frame.setLocationByPlatform(true); frame.setVisible(true); } public static void main(String... args) { SwingUtilities.invokeLater(new Runnable() { public void run() { new PanelExample().createAndDisplayGUI(); } }); } } class ImagePanel extends JPanel { private BufferedImage image; public ImagePanel() { setOpaque(true); setBorder(BorderFactory.createLineBorder(Color.BLACK, 5)); try { image = ImageIO.read(new URL("http://gagandeepbali.uk.to/gaganisonline/images/background.jpg")); } catch(Exception e) { e.printStackTrace(); } createGUI(); } public void createGUI() { setLayout(new GridBagLayout()); JPanel loginPanel = new JPanel(); loginPanel.setOpaque(false); loginPanel.setLayout(new GridLayout(2, 2, 2, 2)); JLabel userLabel = new JLabel("USERNAME : "); userLabel.setForeground(Color.WHITE); JTextField userField = new JTextField(10); JLabel passLabel = new JLabel("PASSWORD : "); passLabel.setForeground(Color.WHITE); JPasswordField passField = new JPasswordField(10); loginPanel.add(userLabel); loginPanel.add(userField); loginPanel.add(passLabel); loginPanel.add(passField); add(loginPanel); System.out.println("I am finished"); } @Override public Dimension getPreferredSize() { return (new Dimension(300, 300)); } public void paintComponent(Graphics g) { super.paintComponent(g); g.drawImage(image, 0, 0, this); } } class BlankPanel extends JPanel { public BlankPanel() { setOpaque(true); setBorder(BorderFactory.createLineBorder(Color.BLACK, 5)); setBackground(Color.WHITE); } @Override public Dimension getPreferredSize() { return (new Dimension(100, 300)); } }