带有JComboBox的Java JTable [英] Java JTable with JComboBox

问题描述

我正在尝试将JComboBox放置在JTable的特定列中. 我有此代码，并且可以正常工作:

I'm trying to place a JComboBox inside a certain column of a JTable. I have this code, and it is working:

    model = new DefaultTableModel();
    JComboBox<String> optionComboCell = new JComboBox<String>();
    optionComboCell.addItem("Option 1");
    optionComboCell.addItem("Option 2");
    optionComboCell.setSelectedIndex(1);


    table = new JTable(model);
    // Adding here all the columns, removed for clarity
    model.addColumn("Options");
    TableColumn optionsColumn = table.getColumn("Options");
    optionsColumn.setCellEditor(new DefaultCellEditor(optionComboCell));

我的问题是，在选择该列中的单元格之前，它不会显示为JComboBox. 加载JFrame时，整个表看起来相同，就好像所有单元格都只有文本一样. 单击时，它会显示组合框的箭头和选项，但是再次取消选中时，它看起来像是常规单元格.

My problem with this, is that it doesn't show as JComboBox until a cell in that column is selected. When the JFrame is loaded, the whole table looks the same, as if all the cells where only text. When clicked, it shows the combo box's arrow and options, but again when deselected, it looks like a regular cell.

有什么办法解决这个问题?

Any way to get around that?

推荐答案

是的，请使用JComboBox渲染单元格:

Yes, use a JComboBox to render your cells:

import java.awt.Component;
import java.util.Enumeration;
import java.util.Vector;

import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;

public class Test4 {

    private static class ComboBoxCellRenderer extends JComboBox implements TableCellRenderer {

        public ComboBoxCellRenderer(int column) {
            for (int i = 0; i < 10; i++) {
                addItem("Cell (" + i + "," + column + ")");
            }
        }

        @Override
        public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
            setSelectedItem(value);
            return this;
        }
    }

    protected void initUI() {
        JFrame frame = new JFrame("test");
        frame.add(getTable());
        frame.pack();
        frame.setVisible(true);
    }

    private Component getTable() {
        Vector<Vector<String>> data = new Vector<Vector<String>>();
        for (int i = 0; i < 10; i++) {
            Vector<String> row = new Vector<String>();
            for (int j = 0; j < 3; j++) {
                row.add("Cell (" + i + "," + j + ")");
            }
            data.add(row);
        }
        Vector<String> columns = new Vector<String>();
        columns.add("Column 1");
        columns.add("Column 2");
        columns.add("Column 3");
        DefaultTableModel model = new DefaultTableModel(data, columns);
        JTable table = new JTable(model);
        table.setRowHeight(20);
        int i = 0;
        Enumeration<TableColumn> c = table.getColumnModel().getColumns();
        while (c.hasMoreElements()) {
            TableColumn column = c.nextElement();
            column.setCellRenderer(new ComboBoxCellRenderer(i));
            i++;
        }
        JScrollPane scroll = new JScrollPane(table);
        scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
        return scroll;
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Test4().initUI();
            }
        });
    }
}

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