Question

我想使用JLabel重新创建表头。 JLabel的外观与系统指定的JTableHeader完全相同。

这是我到目前为止所尝试的：

JLabel header = new JLabel("Title");
header.setOpaque(true);
header.setBackground(UIManager.getColor(new JTableHeader().getBackground()));
header.setBorder(UIManager.getBorder(new JTableHeader().getBorder()));

但是，UIManager会为颜色和边框返回null。

有什么想法吗？

这就是我设置外观的方式：

javax.swing.UIManager.setLookAndFeel(javax.swing.UIManager.getSystemLookAndFeelClassName());

Answer 1

还有更多问题需要获取表头的颜色和边框。每个单元格/列都由TableCellRenderer呈现，这意味着UIManager返回的值可能会被忽略...

例如，以下内容呈现JTableHeader并根据窗口外观下的JLabel返回的值将边框/背景应用于UIManager

enter image description here

正如您所看到的，它们之间存在很大差异

然而，如果您感兴趣的是在滚动窗格上的另一个组件的顶部显示某种“组标题”，则只需在滚动窗格列视图中添加JTableHeader即可直接...

enter image description here

public class TestHeader {

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

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

                TableColumnModel model = new DefaultTableColumnModel();
                final TableColumn column = new TableColumn(0, 250);
                column.setHeaderValue("Test");
                model.addColumn(column);

                JTableHeader header = new JTableHeader();
                header.setColumnModel(model);

                final JTextArea textArea = new JTextArea();

                JScrollPane scrollPane = new JScrollPane(textArea);
                scrollPane.setColumnHeaderView(header);

                textArea.addComponentListener(new ComponentAdapter() {
                    @Override
                    public void componentResized(ComponentEvent e) {
                        column.setWidth(textArea.getWidth());
                    }
                });

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(scrollPane);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }
}

<强>已更新

enter image description here

public class TestHeader {

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

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

                TableColumnModel model = new DefaultTableColumnModel();
                final TableColumn column = new TableColumn(0, 250);
                column.setHeaderValue("I don't see the problem");
                model.addColumn(column);

                final JTableHeader header = new JTableHeader();
                header.setColumnModel(model);

                DefaultTableModel tm = new DefaultTableModel(new Object[]{"A", "B", "C"}, 0);
                tm.addRow(new Object[]{"1", "2", "3", "4"});
                tm.addRow(new Object[]{"5", "6", "7", "8"});
                tm.addRow(new Object[]{"9", "10", "11", "12"});
                tm.addRow(new Object[]{"13", "14", "15", "16"});
                final JTable table = new JTable(tm);

                final JScrollPane scrollPane = new JScrollPane(table);
                /**
                 * For some reason, the header isn't being applied as soon as the
                 * table is added to the scroll pane, so we need to jump our next
                 * request to the end of the of event queue so that it will
                 * occur some time in the future
                 */
                SwingUtilities.invokeLater(new Runnable() {
                    @Override
                    public void run() {
                        scrollPane.setColumnHeaderView(header);
                    }

                });

                table.addComponentListener(new ComponentAdapter() {
                    @Override
                    public void componentResized(ComponentEvent e) {
                        column.setWidth(table.getWidth());
                    }

                });

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(scrollPane);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }

        });
    }

}

Answer 2

在尝试之前，您需要为应用程序设置外观：

header.setBackground(UIManager.getColor(new JTableHeader().getBackground()));
header.setBorder(UIManager.getBorder(new JTableHeader().getBorder()));

你应该首先设置一个外观和感觉：

  try {
    for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
        if ("Nimbus".equals(info.getName())) {
            UIManager.setLookAndFeel(info.getClassName());
            break;
        }
    }
} catch (Exception e) {
    // If Nimbus is not available, you can set the GUI to another look and feel.
}

以下是一个例子：

enter image description here

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.table.JTableHeader;

public class Test {

    public Test() {
        initComponents();
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    //set nimbus look and feel
                    for (UIManager.LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                        if ("Nimbus".equals(info.getName())) {
                            UIManager.setLookAndFeel(info.getClassName());
                            break;
                        }
                    }
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException e) {
                    e.printStackTrace();
                }

                new Test();
            }
        });
    }

    private void initComponents() {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JLabel header = new JLabel("Title");
        header.setBackground(UIManager.getColor(new JTableHeader().getBackground()));
        header.setBorder(UIManager.getBorder(new JTableHeader().getBorder()));

        frame.add(header);

        frame.pack();
        frame.setVisible(true);
    }
}

Answer 3

尝试从UIManager获取默认值：

Color color = UIManager.getColor("TableHeader.background");
Border border = UIManager.getBorder("TableHeader.CellBorder");

Answer 4

我想我会创建一个没有任何行的JTable并在其下方放置JTextPane。它就像魅力一样。

JTextPane textPane = new JTextPane();
JPanel panel = new JPanel(new BorderLayout());

JTable table = new JTable(0, 1);
table.setPreferredScrollableViewportSize(new Dimension(600, 0));
JScrollPane js = new JScrollPane(table)

panel.add(js, BorderLayout.NORTH);
panel.add(new JScrollPane(textPane),BorderLayout.CENTER);

如何设置JLabel的背景和边框与表头相同？

4 个答案: