java在JTable中添加背景图像

Question

我使用了JInternalFrame，因为我添加了JTable。现在我想在JTable中显示背景图像。因此，我在JScrollPane's自定义代码中添加了以下代码

jScrollPane1 = new javax.swing.JScrollPane(ViewBalanceReportTable) {{
    setOpaque(false);
    getViewport().setOpaque(false);
}
@Override
protected void paintComponent(Graphics g) {
    final int imageWidth = image.getIconWidth();
    final int imageHeight = image.getIconHeight();
    final Dimension d = getSize();
    final int x = (d.width - imageWidth)/2;
    final int y = (d.height - imageHeight)/2;
    g.drawImage(image.getImage(), x, y, null, null);
    super.paintComponent(g);
}

}

但它仍然没有显示背景图像，有人能帮我吗

Answer 1

基本上，您需要确保位于框架顶部的所有内容都是透明的（不透明==false）

这个表是一个特例，它不倾向于遵守opaque设置，因为这很容易。相反，我们可以通过使用透明的颜色来欺骗它

如果要在任何类型的框架上绘制，最好替换内容窗格。这将允许您在内容区域内进行绘制，而不是在框架边框或菜单等使用的区域内进行绘制

public class TableWithBackground {

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

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

                JDesktopPane desktopPane = new JDesktopPane();
                BackgroundInternalFrame backgroundInternalFrame = new BackgroundInternalFrame();
                desktopPane.add(backgroundInternalFrame);
                try {
                    backgroundInternalFrame.setMaximum(true);
                } catch (PropertyVetoException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(desktopPane);
                frame.setSize(200, 200);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class BackgroundInternalFrame extends JInternalFrame {

        public BackgroundInternalFrame() {
            super("Hello", true, true, true, true);

            setSize(100, 100);
            setLocation(10, 10);
            setVisible(true);

            setContentPane(new TransparentContentPane());

            JTable table = new JTable();
            table.setModel(new javax.swing.table.DefaultTableModel(
                    new Object[][]{
                        {null, null, null, null},
                        {null, null, null, null},
                        {null, null, null, null},
                        {null, null, null, null}
                    },
                    new String[]{
                        "Title 1", "Title 2", "Title 3", "Title 4"
                    }));

            JScrollPane scrollPane = new JScrollPane(table);
            setLayout(new BorderLayout());
            add(scrollPane);

            scrollPane.setOpaque(false);
            scrollPane.getViewport().setOpaque(false);
            table.setOpaque(false);
            table.setBackground(new Color(255, 255, 255, 0));
        }
    }

    public class TransparentContentPane extends JPanel {

        public TransparentContentPane() {
            setOpaque(false);
        }

        @Override
        protected void paintComponent(Graphics g) {
            Graphics2D g2d = (Graphics2D) g.create();
            g2d.setColor(getBackground());
            g2d.fillRect(0, 0, getWidth(), getHeight());
            g2d.setColor(Color.RED);
            g2d.drawLine(0, 0, getWidth(), getHeight());
            super.paintComponent(g2d); //To change body of generated methods, choose Tools | Templates.
            g2d.dispose();
        }
    }
}

图像表

一个“更简单”的解决方案可能是将图像直接渲染到桌子的背景上。这意味着图像将成为表格的一部分，并随之滚动

这有点棘手，因为JTable#paintComponent不仅会填充背景，还会呈现表格内容

public class TableBackground {

    private BufferedImage background;

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

    public TableBackground() {
        try {
            background = ImageIO.read(new File("C:/Users/swhitehead/Documents/My Dropbox/issue362.jpg"));
        } catch (IOException ex) {
            ex.printStackTrace();
        }

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

                JDesktopPane desktopPane = new JDesktopPane();
                JInternalFrame ittyFrame = new JInternalFrame("Hello", true, true, true, true);
                ittyFrame.setSize(100, 100);
                ittyFrame.setLocation(0, 0);
                ittyFrame.setVisible(true);
                desktopPane.add(ittyFrame);
                try {
                    ittyFrame.setMaximum(true);
                } catch (PropertyVetoException ex) {
                    ex.printStackTrace();
                }

                Object[][] data = new Object[50][4];
                for (int row = 0; row < 50; row++) {
                    for (int col = 0; col < 4; col++) {
                        data[row][col] = col + "." + row;
                    }
                }

                JTable table = new BackgroundImageTable();
                table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
                table.setModel(new javax.swing.table.DefaultTableModel(
                                data,
                                new String[]{
                                    "Title 1", "Title 2", "Title 3", "Title 4"
                                }));

                table.setForeground(Color.WHITE);
                JScrollPane scrollPane = new JScrollPane(table);
                ittyFrame.setLayout(new BorderLayout());
                ittyFrame.add(scrollPane);

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(desktopPane);
                frame.setSize(200, 200);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class BackgroundInternalFrame extends JInternalFrame {

        public BackgroundInternalFrame() {
            super("Hello", true, true, true, true);

            setSize(100, 100);
            setLocation(10, 10);
            setVisible(true);

            setContentPane(new TransparentContentPane());

            JTable table = new JTable();
            table.setModel(new javax.swing.table.DefaultTableModel(
                            new Object[][]{
                                {null, null, null, null},
                                {null, null, null, null},
                                {null, null, null, null},
                                {null, null, null, null}
                            },
                            new String[]{
                                "Title 1", "Title 2", "Title 3", "Title 4"
                            }));

            JScrollPane scrollPane = new JScrollPane(table);
            setLayout(new BorderLayout());
            add(scrollPane);

            scrollPane.setOpaque(false);
            scrollPane.getViewport().setOpaque(false);
            table.setOpaque(false);
            table.setBackground(new Color(255, 255, 255, 0));
        }
    }
}

粘性视口

另一个选项是创建自定义视口。这允许您在大量其他组件的后面呈现内容。这将与您之前遇到的问题相同。桌子及其背景必须设置为透明

这也意味着，通过一些巧妙的工作，你要么“坚持”图像，要么“跟随”内容，这取决于你需要什么

public class TableBackground {

    private BufferedImage background;

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

    public TableBackground() {
        try {
            background = ImageIO.read(new File("C:/Users/swhitehead/Documents/My Dropbox/issue362.jpg"));
        } catch (IOException ex) {
            ex.printStackTrace();
        }

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

                JDesktopPane desktopPane = new JDesktopPane();
                JInternalFrame ittyFrame = new JInternalFrame("Hello", true, true, true, true);
                ittyFrame.setSize(100, 100);
                ittyFrame.setLocation(0, 0);
                ittyFrame.setVisible(true);
                desktopPane.add(ittyFrame);
                try {
                    ittyFrame.setMaximum(true);
                } catch (PropertyVetoException ex) {
                    ex.printStackTrace();
                }

                Object[][] data = new Object[50][4];
                for (int row = 0; row < 50; row++) {
                    for (int col = 0; col < 4; col++) {
                        data[row][col] = col + "." + row;
                    }
                }

                JTable table = new JTable();
                table.setForeground(Color.WHITE);
                table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
                table.setModel(new javax.swing.table.DefaultTableModel(
                                data,
                                new String[]{
                                    "Title 1", "Title 2", "Title 3", "Title 4"
                                }));

                JScrollPane scrollPane = new JScrollPane();
                table.setOpaque(false);
                table.setBackground(new Color(255, 255, 255, 0));
                scrollPane.setViewport(new ImageViewport());
                scrollPane.setViewportView(table);
                ittyFrame.setLayout(new BorderLayout());
                ittyFrame.add(scrollPane);

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(desktopPane);
                frame.setSize(200, 200);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class ImageViewport extends JViewport {

        public ImageViewport() {
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            if (background != null) {
                Rectangle bounds = getViewRect();
                int x = Math.max(0, (bounds.width - background.getWidth()) / 2);
                int y = Math.max(0, (bounds.height - background.getHeight()) / 2);
                g.drawImage(background, x, y, this);
            }
        }
    }
}

很多都取决于你的实际需求