JComboBox 作为自定义 TableCellEditor

Question

我有一张桌子。该表上的更改会更新数据库。该表中的一列由 JComboBox 编辑。单击该列中的任何单元格都会触发 tableChanged 事件。但是，在选择 JComboBox 的项目后需要触发它。如何让 tableChanged 在选择后发生？

public class JIDCellEditor extends AbstractCellEditor implements TableCellEditor {

    JComboBox jComboBox;

    @Override
    public Object getCellEditorValue() {
        return jComboBox.getSelectedItem();
    }

    @Override
    public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
        Vector vector = new Vector();
        vector.add(0);
        for (int i = 0; i < table.getRowCount(); i++) {
            if (!vector.contains(table.getValueAt(i, 0)) && table.getValueAt(i, 3).toString().equals("Female")) {
                vector.add(table.getValueAt(i, 0));
            }
        }
        vector.remove(table.getValueAt(row, 0));
        jComboBox = new JComboBox(vector);
        jComboBox.setSelectedItem(value);
        return jComboBox;
    }
}

Answer 1

我强烈建议使用 SwingX ，它有一个 ComboBoxCellEditor 组件。它本质上是 Sun 的 Swing 组件应有功能的孵化器。我不知道该项目是否仍在积极开发中，但它已经成熟，并且我已经在很多项目中使用了它。

如果出于某种原因，您不能或不想使用外部库，这里是他们的代码（修改了部分以删除自定义 SwingX 功能），注释完好无损：

注意：该库是 GPL 代码。

/*
 * $Id: ComboBoxCellEditor.java 3738 2010-07-27 13:56:28Z bierhance $
 * 
 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, California 95054, U.S.A. All rights reserved.
 * 
 * This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

import java.awt.event.ActionEvent;
import java.awt.event.MouseEvent;
import java.util.EventObject;

import javax.swing.DefaultCellEditor;
import javax.swing.JComboBox;

/**
 * <p>
 * This is a cell editor that can be used when a combo box (that has been set up for automatic completion) is to be used in a JTable. The
 * {@link javax.swing.DefaultCellEditor DefaultCellEditor} won't work in this case, because each time an item gets selected it stops cell
 * editing and hides the combo box.
 * </p>
 * <p>
 * Usage example:
 * </p>
 * <p>
 * 
     * <pre>
 * <code>
 * JTable table = ...;
 * JComboBox comboBox = ...;
 * ...
 * TableColumn column = table.getColumnModel().getColumn(0);
 * column.setCellEditor(new ComboBoxCellEditor(comboBox));
 * </code>
 * </pre>
 * 
 * </p>
 */
public class ComboBoxCellEditor extends DefaultCellEditor {

    /**
     * Creates a new ComboBoxCellEditor.
     * 
     * @param comboBox the comboBox that should be used as the cell editor.
     */
    public ComboBoxCellEditor(final JComboBox comboBox) {
        super(comboBox);

        comboBox.removeActionListener(this.delegate);

        this.delegate = new EditorDelegate() {
            @Override
            public void setValue(final Object value) {
                comboBox.setSelectedItem(value);
            }

            @Override
            public Object getCellEditorValue() {
                return comboBox.getSelectedItem();
            }

            @Override
            public boolean shouldSelectCell(final EventObject anEvent) {
                if (anEvent instanceof MouseEvent) {
                    final MouseEvent e = (MouseEvent) anEvent;
                    return e.getID() != MouseEvent.MOUSE_DRAGGED;
                }
                return true;
            }

            @Override
            public boolean stopCellEditing() {
                if (comboBox.isEditable()) {
                    // Commit edited value.
                    comboBox.actionPerformed(new ActionEvent(ComboBoxCellEditor.this, 0, ""));
                }
                return super.stopCellEditing();
            }

            @Override
            public void actionPerformed(final ActionEvent e) {
                ComboBoxCellEditor.this.stopCellEditing();
            }
        };
        comboBox.addActionListener(this.delegate);
    }
}

Answer 2

现在可以了。每次调用 getTableCellEditorComponent 方法时，都需要重新初始化 JComboBox。并且在此 JComboBox 的 itemstatechange 中 stopCellEditing() 方法必须通知侦听器在选择项目时已完成编辑。这使得 TableModelListener fireTableChanged 事件。 （已修复）但是，当您在单击另一个 JComboBox 而不进行选择后单击一个 JComboBox 时，它也会触发该事件。 （/已修复）

编辑：以下代码是最新版本。通过此 TableModelListener，仅当选择某个项目时才会收到通知。上述问题已解决。这是因为默认的 stopCellEditing() 方法总是返回 true。这会导致单元格编辑以意外的方式停止。必须根据需要重写它并 fireEditingStopped();必须用于通知TableModelListener

public class JIDCellEditor extends AbstractCellEditor implements TableCellEditor {

    private JComboBox jComboBox = new JComboBox();
    boolean cellEditingStopped = false;

    @Override
    public Object getCellEditorValue() {
        return jComboBox.getSelectedItem();
    }

    @Override
    public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
        Vector vector = new Vector();
        ArrayList<Integer> arrayList = new ArrayList<Integer>();
        arrayList.add(Integer.parseInt(value.toString()));
        vector.add(0);
        for (int i = 0; i < table.getRowCount(); i++) {
            if (!vector.contains(table.getValueAt(i, 0)) && table.getValueAt(i, 3).toString().equals("Sheep")) {
                vector.add(table.getValueAt(i, 0));
            }
        }
        vector.remove(table.getValueAt(row, 0));

        for (int i = 0; i < vector.size(); i++) {
        }
        jComboBox = new JComboBox(vector);
        jComboBox.setSelectedItem(value);

        jComboBox.addItemListener(new ItemListener() {

            @Override
            public void itemStateChanged(ItemEvent e) {
                if (e.getStateChange() == ItemEvent.SELECTED) {
                    fireEditingStopped();
                }
            }
        });
        jComboBox.addPopupMenuListener(new PopupMenuListener() {

            @Override
            public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
                cellEditingStopped = false;
            }

            @Override
            public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
                cellEditingStopped = true;
                fireEditingCanceled();
            }

            @Override
            public void popupMenuCanceled(PopupMenuEvent e) {

            }
        });
        return jComboBox;
    }

    @Override
    public boolean stopCellEditing() {
        return cellEditingStopped;
    }
}