如何在jTable中的某些单元格上获取jComboBox？

Question

I'm trying to create a jComboBox in a certain cell from a jTable. If on the same line in column 4 you have the value "FN", you will have on the column 5 a jComboBox with 3 options ("SSAA-MM-JJ", "SSAA/MM/JJ", "SAAMMJJ"), but all the other cells on column 5 must remain untouched if the value from the cell on column 4 on the same row is not "FN".

What do I do wrong?

Here is what i've tried:

package rdjcsv;

import java.awt.Component;
import javax.swing.AbstractCellEditor;
import javax.swing.DefaultCellEditor;
import javax.swing.JComboBox;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.table.TableCellEditor;

/**
*
* @author acucu
 */
class MyCellEditor extends AbstractCellEditor implements TableCellEditor {

DefaultCellEditor other = new DefaultCellEditor(new JTextField());
DefaultCellEditor checkbox = new DefaultCellEditor(new JComboBox(new Object[] {"abc"}));

private DefaultCellEditor lastSelected;

@Override
public Object getCellEditorValue() {

    return lastSelected.getCellEditorValue();
}

@Override
public Component getTableCellEditorComponent(JTable table,
        Object value, boolean isSelected, int row, int column) {
    if(column == 4 && table.getValueAt(row, column-1).toString().contains("FN")){


    if(row == 0) {
        lastSelected = checkbox;
        return checkbox.getTableCellEditorComponent(table, value, isSelected, row, column);
    }
    lastSelected = other;
    return other.getTableCellEditorComponent(table, value, isSelected, row, column);
}
   return other.getTableCellEditorComponent(table, value, isSelected, row, column);
}

}

And the call:

String[] values = new String[] {"SSAA-MM-JJ", "SSAA/MM/JJ", "SAAMMJJ"};
  TableColumn col = jTable1.getColumnModel().getColumn(4);
col.setCellEditor(new MyComboBoxEditor(values));
col.setCellRenderer(new MyComboBoxRenderer(values));

The output: jComboBox es on every cell from the 5th column.

Answer 1

Your image is showing the output from the cell renderer, not the cell editor, since only one cell editor should be visible at any time. You don't want the renderer to look like a JComboBox but rather to display as text, as a label. This suggests other problems with your program.

Other issues:

• Your code above risks a NPE since lastSelected can be null when it starts out.
• Why are you checking that row == 0? Do you to use the JComboBox editor for the first row only?
• Post your minimal example program if still stuck,

for example, mine:

import java.awt.BorderLayout;
import java.awt.Component;

import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellEditor;

@SuppressWarnings("serial")
public class ComboEditorEg extends JPanel {
    private MyTableModel model = new MyTableModel();
    private JTable table = new JTable(model);

    public ComboEditorEg() {
        for (int i = 0; i < 10; i++) {
            String textA = i % 2 == 0 ? "SA" : "FN";
            String textB = i % 2 == 0 ? "A" : "B";

            Object[] row = new String[] { textA, textB };
            model.addRow(row);
        }

        table.getColumnModel().getColumn(1).setCellEditor(new MyCellEditor());

        setLayout(new BorderLayout());
        add(new JScrollPane(table));
    }

    private static void createAndShowGui() {
        ComboEditorEg mainPanel = new ComboEditorEg();

        JFrame frame = new JFrame("ComboEditorEg");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            createAndShowGui();
        });
    }
}

@SuppressWarnings("serial")
class MyTableModel extends DefaultTableModel {
    public static final String[] COL_NAMES = { "Foo 1", "Foo 2" };

    public MyTableModel() {
        super(COL_NAMES, 0);
    }

    @Override
    public Class<?> getColumnClass(int columnIndex) {
        return String.class;
    }
}

@SuppressWarnings("serial")
class MyCellEditor extends AbstractCellEditor implements TableCellEditor {

    DefaultCellEditor other = new DefaultCellEditor(new JTextField());
    DefaultCellEditor checkbox = new DefaultCellEditor(new JComboBox<String>(new String[] { "abc",
            "def", "ghi" }));

    private DefaultCellEditor lastSelected = other; // so it's not null

    @Override
    public Object getCellEditorValue() {

        return lastSelected.getCellEditorValue();
    }

    @Override
    public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected,
            int row, int column) {
        if (table.getValueAt(row, column - 1).toString().contains("FN")) {
            lastSelected = checkbox;
            return checkbox.getTableCellEditorComponent(table, value, isSelected, row, column);
        }
        return other.getTableCellEditorComponent(table, value, isSelected, row, column);
    }

}