Question

我有一个SQL数据库，我正在开发一个允许我添加/删除/修改记录的程序。我已经设法添加了我正在编辑/删除它们的记录。

我想在表格中显示现有记录，因此我使用的是jTable。我在网上找到了一些代码并对其进行了修改以拉出记录并在jtable中显示它们但我不知道如何编写右键并显示弹出菜单。

在该弹出菜单中，我想显示删除记录和修改记录等选项。

这是我使用make jTable并显示数据的代码：

 private void menuDeleteAuthorActionPerformed(java.awt.event.ActionEvent evt) {                                                 
    TableFromDatabase deleteAuthor = new TableFromDatabase();
    deleteAuthor.pack();
    deleteAuthor.setVisible(true);

    Vector columnNames = new Vector();
    Vector data = new Vector();

    try
    {

        Connection connection = DriverManager.getConnection( url, user, password );

        //  Read data from a table

        String sql = "SELECT * FROM Authors";
        Statement stmt = connection.createStatement();
        ResultSet rs = stmt.executeQuery( sql );
        ResultSetMetaData md = rs.getMetaData();
        int columns = md.getColumnCount();

        //  Get column names

        for (int i = 1; i <= columns; i++)
        {
            columnNames.addElement( md.getColumnName(i) );
        }

        //  Get row data

        while (rs.next())
        {
            Vector row = new Vector(columns);

            for (int i = 1; i <= columns; i++)
            {
                row.addElement( rs.getObject(i) );
            }

            data.addElement( row );
        }

        rs.close();
        stmt.close();
        connection.close();
    }
    catch(Exception e)
    {
        System.out.println( e );
    }

    //  Create table with database data

    JTable table = new JTable(data, columnNames)
    {
        public Class getColumnClass(int column)
        {
            for (int row = 0; row < getRowCount(); row++)
            {
                Object o = getValueAt(row, column);

                if (o != null)
                {
                    return o.getClass();
                }
            }

            return Object.class;
        }
    };

    JScrollPane scrollPane = new JScrollPane( table );
    getContentPane().add( scrollPane );

    JPanel buttonPanel = new JPanel();
    getContentPane().add( buttonPanel, BorderLayout.SOUTH );
}

我是Java的新手，所以请善意回复。提前感谢大家的帮助！

Answer 1

这是一个如何做到这一点的例子。实现此目的的最简单方法是直接在JTable上设置JPopupMenu。

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Arrays;
import java.util.Vector;

import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;

public class TestTableRightClick {

    protected void initUI() {
        final JFrame frame = new JFrame(TestTableRightClick.class.getSimpleName());
        Vector<String> columns = new Vector<String>(Arrays.asList("Name", "Age"));
        Vector<Vector<String>> data = new Vector<Vector<String>>();
        for (int i = 0; i < 50; i++) {
            Vector<String> row = new Vector<String>();
            for (int j = 0; j < columns.size(); j++) {
                row.add("Cell " + (i + 1) + "," + (j + 1));
            }
            data.add(row);
        }
        final JTable table = new JTable(data, columns);
        final JPopupMenu popupMenu = new JPopupMenu();
        JMenuItem deleteItem = new JMenuItem("Delete");
        deleteItem.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                JOptionPane.showMessageDialog(frame, "Right-click performed on table and choose DELETE");
            }
        });
        popupMenu.add(deleteItem);
        table.setComponentPopupMenu(popupMenu);
        frame.add(new JScrollPane(table), BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);
    }

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

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

如果您想自动选择右键单击的行，请添加以下代码段：

popupMenu.addPopupMenuListener(new PopupMenuListener() {

            @Override
            public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
                SwingUtilities.invokeLater(new Runnable() {
                    @Override
                    public void run() {
                        int rowAtPoint = table.rowAtPoint(SwingUtilities.convertPoint(popupMenu, new Point(0, 0), table));
                        if (rowAtPoint > -1) {
                            table.setRowSelectionInterval(rowAtPoint, rowAtPoint);
                        }
                    }
                });
            }

            @Override
            public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
                // TODO Auto-generated method stub

            }

            @Override
            public void popupMenuCanceled(PopupMenuEvent e) {
                // TODO Auto-generated method stub

            }
        });

Answer 2

JTable的一个问题是右键单击不会改变行选择。因此，如果您有一个适用于特定行的Action，则需要在右键单击该行之前先单击该行以显示弹出菜单。

如果您希望在右键单击的位置选择行，则可以使用以下代码：

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class TableRightClick extends JFrame implements ActionListener
{
    JPopupMenu popup;

    public TableRightClick()
    {
        popup = new JPopupMenu();
        popup.add( new JMenuItem("Do Something1") );
        popup.add( new JMenuItem("Do Something2") );
        popup.add( new JMenuItem("Do Something3") );
        JMenuItem menuItem = new JMenuItem("ActionPerformed");
        menuItem.addActionListener( this );
        popup.add( menuItem );

        JTable table = new JTable(50, 5);
        table.addMouseListener( new MouseAdapter()
        {
            public void mousePressed(MouseEvent e)
            {
                System.out.println("pressed");
            }

            public void mouseReleased(MouseEvent e)
            {
                if (e.isPopupTrigger())
                {
                    JTable source = (JTable)e.getSource();
                    int row = source.rowAtPoint( e.getPoint() );
                    int column = source.columnAtPoint( e.getPoint() );

                    if (! source.isRowSelected(row))
                        source.changeSelection(row, column, false, false);

                    popup.show(e.getComponent(), e.getX(), e.getY());
                }
            }
        });
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        getContentPane().add( new JScrollPane(table) );
    }

    public void actionPerformed(ActionEvent e)
    {
        Component c = (Component)e.getSource();
        JPopupMenu popup = (JPopupMenu)c.getParent();
        JTable table = (JTable)popup.getInvoker();
        System.out.println(table.getSelectedRow() + " : " + table.getSelectedColumn());
    }

    public static void main(String[] args)
    {
        TableRightClick frame = new TableRightClick();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setLocationRelativeTo( null );
        frame.setVisible( true );
    }
}

Answer 3

另一个问题是上下文菜单是动态的，您的解决方案不涉及根据点击的行更改菜单

    popupMenu.addPopupMenuListener(new PopupMenuListener() 
    {
        @Override
        public void popupMenuWillBecomeVisible(PopupMenuEvent e) // juste pour selectionner la row quant on right click, putain de swing de merde
        { 
            int rowAtPoint = table.rowAtPoint(SwingUtilities.convertPoint(popupMenu, new Point(0, 0), table));
            generateTablePopupMenu(rowAtPoint); <<<<<<<<<<<< here
            SwingUtilities.invokeLater(new Runnable() 
            ...

jTable右键单击弹出菜单

3 个答案: