java - JComboBox 的 KeyListeners，用作表中的单元格编辑器

Question

如果这听起来像是一个基本问题，我很抱歉，但我对 java 还比较陌生。我有一个 JComboBox，我从数据库填充它，然后在 JTable 中使用它。我使用以下代码来做到这一点:

itemEditortxt = new JComboBox(buildComboBoxmodel("SELECT item_name FROM items ORDER BY item_name"));
AutoCompleteDecorator.decorate(itemEditortxt);
TableColumn ledgerColumn = invoicePurchasedTable.getColumnModel().getColumn(0);
ledgerColumn.setCellEditor(new ComboBoxCellEditor(itemEditortxt));

我正在尝试向 JComboBox 添加关键监听器，但由于某种原因，当焦点位于使用 JComboBox 的单元格上时，当我按任意键时，它们不会被调用。以下是我添加垃圾的方法:

itemEditortxt.addKeyListener(new KeyListener() {
        @Override
        public void keyPressed(KeyEvent e) {System.out.print("line1");}
        @Override
        public void keyReleased(KeyEvent e) {System.out.print("line2");}
        @Override
        public void keyTyped(KeyEvent e) {System.out.print("line3");}
    });

有人可以告诉我我做错了什么吗？谢谢。以下是 SSCCE。类似的JComboBox有两种，一种是正常添加，一种是作为单元格编辑器使用。在第一个中，用户可以使用键盘箭头，然后按 ENTER 进行选择。表中的情况并非如此。谢谢:

package sp2;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;
import javax.swing.table.*;
import org.jdesktop.swingx.autocomplete.*;

class InvoicePurchasedModel extends DefaultTableModel {
public InvoicePurchasedModel (Vector<Vector<Object>> data, Vector<String> columnNames) {
    super(data, columnNames);
}

@Override
public Class getColumnClass(int col) {
    if (col == 0) 
        return String.class;
    else
        return Double.class;   
}
}

public class SP2 {    
JFrame mainPage;
JTabbedPane jtp;
JPanel mainPanel;
JPanel purchasedInvoicesPanel;    
RXTable invoicePurchasedTable;
DefaultTableModel invoicePurchasedtm;
JComboBox itemEditortxt;
JComboBox itemEditortxt2;

SP2() {
    mainPage = new JFrame("System");
    mainPage.getContentPane().setLayout(new GridLayout());
    mainPage.setSize(1200, 1200);
    mainPage.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    createTabs();    
    mainPage.setVisible(true);
}

void createTabs() {
    jtp = new JTabbedPane();
    mainPanel = new JPanel();
    mainPanel.setLayout(new GridLayout());
    mainPage.getContentPane().add(jtp);      
    purchasedInvoicesPanel = new JPanel();
    jtp.addTab("Purchased", purchasedInvoicesPanel);
    invoicePurchasedtm = buildInvoicePurchasedTableModel();
    invoicePurchasedTable = new RXTable(invoicePurchasedtm) {
        private final KeyStroke tabKeyStroke = KeyStroke.getKeyStroke(KeyEvent.VK_TAB, 0); 
            public void changeSelection(int row, int column, boolean toggle, boolean extend)
            {
                super.changeSelection(row, column, toggle, extend);
                if (editCellAt(row, column))
                {
                    Component editor = getEditorComponent();
                    editor.requestFocusInWindow();
                }
            }
        }; 
    invoicePurchasedTable.setCellSelectionEnabled(true);
    invoicePurchasedTable.setSelectAllForEdit(true);
    purchasedInvoicesPanel.setLayout(new BoxLayout(purchasedInvoicesPanel, BoxLayout.PAGE_AXIS));
    JPanel purchasedInvoicesPanel1 = new JPanel();
    JPanel purchasedInvoicesPanel2 = new JPanel();
    purchasedInvoicesPanel.add(purchasedInvoicesPanel1);
    purchasedInvoicesPanel.add(purchasedInvoicesPanel2);
    JScrollPane invoicePurchasedscrollPane = new JScrollPane(invoicePurchasedTable);
    invoicePurchasedTable.setPreferredScrollableViewportSize(new Dimension(1000, 400));
    String[] names = {"aa", "aa1", "aa2", "bb", "bb1", "bb2"};
    itemEditortxt = new JComboBox(names);
    itemEditortxt2 = new JComboBox(names);
    AutoCompleteDecorator.decorate(itemEditortxt);
    AutoCompleteDecorator.decorate(itemEditortxt2);
    TableColumn ledgerColumn = invoicePurchasedTable.getColumnModel().getColumn(0);
    ledgerColumn.setCellEditor(new ComboBoxCellEditor(itemEditortxt));
    purchasedInvoicesPanel1.add(itemEditortxt2);
    purchasedInvoicesPanel2.add(invoicePurchasedscrollPane);
}

public static DefaultTableModel buildInvoicePurchasedTableModel() {
    Vector<String> columnNames = new Vector<String>();
    columnNames.add("Item");
    columnNames.add("Quantity");
    columnNames.add("Unit Price");
    columnNames.add("Amount");
    Vector<Vector<Object>> data = new Vector<Vector<Object>>();
    Vector<Object> vector = new Vector<Object>();
    vector.add("");
    vector.add(0.00);
    vector.add(0.00);
    vector.add(0.00);
    data.add(vector);
    return new InvoicePurchasedModel(data, columnNames);
}

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    // TODO code application logic here
    SwingUtilities.invokeLater(new Runnable() {
       public void run() {
           new SP2();
       } 
    });
}
}

Answer 1

"I am trying to add key listeners to the JComboBox but for some reason they are not being called when I press any key when the focus is on the cell which uses the JComboBox."

我认为您可能想要做的是将监听器添加到组合框的“文本字段”。您需要做的第一件事是实际获取编辑器组件。然后您可以将 DocumentListener 添加到 JTextComponent

的 Document

JTextComponent editor = (JTextComponent) comboBox.getEditor().getEditorComponent();
editor.getDocument().addDocumentListener(new DocumentListener(){
    ...
});