java - 在 JTable 中选择单行两次不会第二次调用 ListSelectionListener.valueChanged()

Question

我正在尝试使用复选框(在 JTable 的每一行中)中的值来操作数据。但是，当我第二次单击同一行的复选框时，不会调用监听器 valueChanged 方法。

可以通过从oracle网站下载表示例轻松重现here

尝试单击同一行的复选框两次。当我们第二次单击该复选框时，控制台日志不会发生变化。

解决方案:借助提供的评论和解决方案。使用 TableModelListener 已经达到了我的目的。

Answer 1

Yes . I did tried with the table model listener but it is also behaving in the same manner .

对我有用...

修改TableSelectionDemo添加 TableModelListener 支持

import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Dimension;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.TableModel;

public class TableSelectionDemo extends JPanel
        implements ActionListener {

    private JTable table;
    private JCheckBox rowCheck;
    private JCheckBox columnCheck;
    private JCheckBox cellCheck;
    private ButtonGroup buttonGroup;
    private JTextArea output;

    public TableSelectionDemo() {
        super();
        setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));

        TableModel model = new MyTableModel();
        model.addTableModelListener(new TableModelListener() {
            @Override
            public void tableChanged(TableModelEvent e) {
                output.append("Table changed");
                output.append("\n");
            }
        });

        table = new JTable(model);
        table.setPreferredScrollableViewportSize(new Dimension(500, 70));
        table.setFillsViewportHeight(true);
        table.getSelectionModel().addListSelectionListener(new RowListener());
        table.getColumnModel().getSelectionModel().
                addListSelectionListener(new ColumnListener());
        add(new JScrollPane(table));

        add(new JLabel("Selection Mode"));
        buttonGroup = new ButtonGroup();
        addRadio("Multiple Interval Selection").setSelected(true);
        addRadio("Single Selection");
        addRadio("Single Interval Selection");

        add(new JLabel("Selection Options"));
        rowCheck = addCheckBox("Row Selection");
        rowCheck.setSelected(true);
        columnCheck = addCheckBox("Column Selection");
        cellCheck = addCheckBox("Cell Selection");
        cellCheck.setEnabled(false);

        output = new JTextArea(5, 40);
        output.setEditable(false);
        add(new JScrollPane(output));
    }

    private JCheckBox addCheckBox(String text) {
        JCheckBox checkBox = new JCheckBox(text);
        checkBox.addActionListener(this);
        add(checkBox);
        return checkBox;
    }

    private JRadioButton addRadio(String text) {
        JRadioButton b = new JRadioButton(text);
        b.addActionListener(this);
        buttonGroup.add(b);
        add(b);
        return b;
    }

    public void actionPerformed(ActionEvent event) {
        String command = event.getActionCommand();
        //Cell selection is disabled in Multiple Interval Selection
        //mode. The enabled state of cellCheck is a convenient flag
        //for this status.
        if ("Row Selection".equals(command)) {
            table.setRowSelectionAllowed(rowCheck.isSelected());
            //In MIS mode, column selection allowed must be the
            //opposite of row selection allowed.
            if (!cellCheck.isEnabled()) {
                table.setColumnSelectionAllowed(!rowCheck.isSelected());
            }
        } else if ("Column Selection".equals(command)) {
            table.setColumnSelectionAllowed(columnCheck.isSelected());
            //In MIS mode, row selection allowed must be the
            //opposite of column selection allowed.
            if (!cellCheck.isEnabled()) {
                table.setRowSelectionAllowed(!columnCheck.isSelected());
            }
        } else if (command == "Cell Selection") {
            table.setCellSelectionEnabled(cellCheck.isSelected());
        } else if (command == "Multiple Interval Selection") {
            table.setSelectionMode(
                    ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
            //If cell selection is on, turn it off.
            if (cellCheck.isSelected()) {
                cellCheck.setSelected(false);
                table.setCellSelectionEnabled(false);
            }
            //And don't let it be turned back on.
            cellCheck.setEnabled(false);
        } else if ("Single Interval Selection".equals(command)) {
            table.setSelectionMode(
                    ListSelectionModel.SINGLE_INTERVAL_SELECTION);
            //Cell selection is ok in this mode.
            cellCheck.setEnabled(true);
        } else if (command == "Single Selection") {
            table.setSelectionMode(
                    ListSelectionModel.SINGLE_SELECTION);
            //Cell selection is ok in this mode.
            cellCheck.setEnabled(true);
        }

        //Update checkboxes to reflect selection mode side effects.
        rowCheck.setSelected(table.getRowSelectionAllowed());
        columnCheck.setSelected(table.getColumnSelectionAllowed());
        if (cellCheck.isEnabled()) {
            cellCheck.setSelected(table.getCellSelectionEnabled());
        }
    }

    private void outputSelection() {
        output.append(String.format("Lead: %d, %d. ",
                table.getSelectionModel().getLeadSelectionIndex(),
                table.getColumnModel().getSelectionModel().
                        getLeadSelectionIndex()));
        output.append("Rows:");
        for (int c : table.getSelectedRows()) {
            output.append(String.format(" %d", c));
        }
        output.append(". Columns:");
        for (int c : table.getSelectedColumns()) {
            output.append(String.format(" %d", c));
        }
        output.append(".\n");
    }

    private class RowListener implements ListSelectionListener {

        public void valueChanged(ListSelectionEvent event) {
            if (event.getValueIsAdjusting()) {
                return;
            }
            output.append("ROW SELECTION EVENT. ");
            outputSelection();
        }
    }

    private class ColumnListener implements ListSelectionListener {

        public void valueChanged(ListSelectionEvent event) {
            if (event.getValueIsAdjusting()) {
                return;
            }
            output.append("COLUMN SELECTION EVENT. ");
            outputSelection();
        }
    }

    class MyTableModel extends AbstractTableModel {

        private String[] columnNames = {"First Name",
            "Last Name",
            "Sport",
            "# of Years",
            "Vegetarian"};
        private Object[][] data = {
            {"Kathy", "Smith",
                "Snowboarding", new Integer(5), new Boolean(false)},
            {"John", "Doe",
                "Rowing", new Integer(3), new Boolean(true)},
            {"Sue", "Black",
                "Knitting", new Integer(2), new Boolean(false)},
            {"Jane", "White",
                "Speed reading", new Integer(20), new Boolean(true)},
            {"Joe", "Brown",
                "Pool", new Integer(10), new Boolean(false)}
        };

        public int getColumnCount() {
            return columnNames.length;
        }

        public int getRowCount() {
            return data.length;
        }

        public String getColumnName(int col) {
            return columnNames[col];
        }

        public Object getValueAt(int row, int col) {
            return data[row][col];
        }

        /*
         * JTable uses this method to determine the default renderer/
         * editor for each cell.  If we didn't implement this method,
         * then the last column would contain text ("true"/"false"),
         * rather than a check box.
         */
        public Class getColumnClass(int c) {
            return getValueAt(0, c).getClass();
        }

        /*
         * Don't need to implement this method unless your table's
         * editable.
         */
        public boolean isCellEditable(int row, int col) {
            //Note that the data/cell address is constant,
            //no matter where the cell appears onscreen.
            if (col < 2) {
                return false;
            } else {
                return true;
            }
        }

        /*
         * Don't need to implement this method unless your table's
         * data can change.
         */
        public void setValueAt(Object value, int row, int col) {
            data[row][col] = value;
            fireTableCellUpdated(row, col);
        }

    }

    /**
     * Create the GUI and show it. For thread safety, this method should be
     * invoked from the event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Disable boldface controls.
        UIManager.put("swing.boldMetal", Boolean.FALSE);

        //Create and set up the window.
        JFrame frame = new JFrame("TableSelectionDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        TableSelectionDemo newContentPane = new TableSelectionDemo();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}