java - 如何在jTable中的某个单元格上获取jComboBox？

Question

我正在尝试从 jTable 的某个单元格中创建 jComboBox。如果在第 4 列的同一行上您有值“FN”，则您将在第 5 列上看到一个带有 3 个选项的 jComboBox(“SSAA-MM-JJ”、“SSAA/MM/JJ”、“SAAMMJJ”)，但如果同一行第 4 列单元格的值不是“FN”，则第 5 列上的所有其他单元格必须保持不变。

我做错了什么？

这是我尝试过的:

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);
}

}

还有电话:

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));

输出:jComboBox 位于第 5 列的每个单元格上。

Answer 1

您的图像显示的是单元格渲染器的输出，而不是单元格编辑器的输出，因为任何时候都应该只有一个单元格编辑器可见。您不希望渲染器看起来像 JComboBox，而是显示为文本、标签。这表明您的程序存在其他问题。

其他问题:

• 上面的代码存在 NPE 风险，因为 lastSelected 在启动时可能为 null。
• 为什么要检查该行 == 0？您是否仅对第一行使用 JComboBox 编辑器？
• 如果仍然卡住，请发布您的最小示例程序，

例如我的:

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);
    }

}