如何使 JTable 单元格中的 JButton 可点击？

Question

我有一个带有自定义单元格渲染器的 JTable。该单元格是一个 JPanel，其中包含一个 JTextField 和一个 JButton。 JTextField 包含一个整数，当用户点击 JButton 时，整数应该增加。

问题是当我将它放在 JTable 单元格中时，无法单击 JButton。我怎样才能让它可以点击？

这是我的测试代码：

public class ActiveTable extends JFrame {

    public ActiveTable() {
        RecordModel model = new RecordModel();
        model.addRecord(new Record());
        JTable table = new JTable(model);
        EditorAndRenderer editorAndRenderer = new EditorAndRenderer();
        table.setDefaultRenderer(Object.class, editorAndRenderer);
        table.setDefaultEditor(Object.class, editorAndRenderer);
        table.setRowHeight(38);

        add(new JScrollPane(table));
        setPreferredSize(new Dimension(600, 400));
        pack();
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setTitle("Active Table");
        setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new ActiveTable();
            }
        });
    }

    class RecordModel extends AbstractTableModel {

        private final List<Record> records = new ArrayList<Record>();

        @Override
        public int getColumnCount() {
            return 1;
        }

        @Override
        public int getRowCount() {
            return records.size();
        }

        @Override
        public Object getValueAt(int rowIndex, int columnIndex) {
            return records.get(rowIndex);
        }

        public void addRecord(Record r) {
            records.add(r);
            fireTableRowsInserted(records.size()-1, records.size()-1);
        }

    }

    class Record {
        private int count = 1;
        public int getCount() { return count; }
        public void increase() { count = count + 1; }
    }

    class CellPanel extends JPanel {
        private Record record;
        private final JTextField field = new JTextField(8);
        private final Action increaseAction = new AbstractAction("+") {
            public void actionPerformed(ActionEvent e) {
                record.increase();
                field.setText(record.getCount()+"");
                JTable table = (JTable) SwingUtilities.getAncestorOfClass(JTable.class, (Component) e.getSource());
                table.getCellEditor().stopCellEditing();
            }
        };
        private final JButton button = new JButton(increaseAction);

        public CellPanel() {
            add(field);
            add(button);
        }

        public void setRecord(Record r) {
            record = r;
            field.setText(record.getCount()+"");
        }

        public Record getRecord() {
            return record;
        }
    }

    class EditorAndRenderer extends AbstractCellEditor implements TableCellEditor, TableCellRenderer {

        private final CellPanel renderer = new CellPanel();
        private final CellPanel editor = new CellPanel();

        @Override
        public Component getTableCellRendererComponent(JTable table, Object value,
                boolean isSelected, boolean hasFocus, int row, int column) {
            renderer.setRecord((Record) value);
            return renderer;
        }

        @Override
        public Component getTableCellEditorComponent(JTable table, Object value,
                boolean isSelected, int row, int column) {
            editor.setRecord((Record) value);
            return editor;
        }

        @Override
        public Object getCellEditorValue() {
            return editor.getRecord();
        }

        @Override
        public boolean isCellEditable(EventObject ev) {
            return true;
        }

        @Override
        public boolean shouldSelectCell(EventObject ev) {
            return false;
        }
    }
}

Answer 1

渲染器只是用于绘制单元格的显示器。您需要一个允许您进行更改的编辑器组件。

看看：

http://download.oracle.com/javase/6/docs/api/javax/swing/table/TableCellEditor.html

Answer 2

这是使用ButtonColumn 的一种方式。

public class TableTest extends JFrame {

    public TableTest() {
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JTable table = new JTable(new TestModel());
        table.getColumnModel().getColumn(1).setPreferredWidth(3);
        table.getColumnModel().getColumn(2).setPreferredWidth(3);
        this.add(new JScrollPane(table));
        Action increase = new AbstractAction("+") {

            @Override
            public void actionPerformed(ActionEvent e) {
                JTable table = (JTable) e.getSource();
                int row = Integer.valueOf(e.getActionCommand());
                TestModel model = (TestModel) table.getModel();
                model.increment(row, 0);
            }
        };
        ButtonColumn inc = new ButtonColumn(table, increase, 1);
        Action decrease = new AbstractAction("-") {

            @Override
            public void actionPerformed(ActionEvent e) {
                JTable table = (JTable) e.getSource();
                int row = Integer.valueOf(e.getActionCommand());
                TestModel model = (TestModel) table.getModel();
                model.decrement(row, 0);
            }
        };
        ButtonColumn dec = new ButtonColumn(table, decrease, 2);
        pack();
    }

    public static void main(String[] args) {
        new TableTest().setVisible(true);
    }
}

class TestModel extends AbstractTableModel {

    List<TestRecord> records = new LinkedList<TestRecord>();

    private static class TestRecord {

        private int val = 0;
    }

    public void increment(int row, int col) {
        records.get(row).val++;
        fireTableCellUpdated(row, 0);
    }

    public void decrement(int row, int col) {
        records.get(row).val--;
        fireTableCellUpdated(row, 0);
    }

    public TestModel() {
        records.add(new TestRecord());
        records.add(new TestRecord());
    }

    @Override
    public Class<?> getColumnClass(int col) {
        if (col == 0) {
            return Integer.class;
        } else {
            return ButtonColumn.class;
        }
    }

    @Override
    public boolean isCellEditable(int row, int col) {
        return true;
    }

    @Override
    public int getColumnCount() {
        return 3;
    }

    @Override
    public int getRowCount() {
        return records.size();
    }

    @Override
    public Object getValueAt(int row, int col) {
        if (col == 0) {
            return records.get(row).val;
        } else if (col == 1) {
            return "+";
        } else {
            return "-";
        }
    }
}

Answer 3

我的上一个示例基于 mKrobels 对How to implement dynamic GUI in swing 的回答提供的代码

问题中他和我的示例之间的主要区别在于他使用DefaultTableModel 而我使用AbstractTableModel。他的例子确实有效，但不是我的。

我找到的解决方案是我必须在 TableModel 中实现isCellEditable()，所以添加了这个方法后，我的示例就可以了：

@Override
public boolean isCellEditable(int rowIndex, int columnIndex) {
    return true;
}