23

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。我已经设法添加我正在编辑/删除它们的记录。

我想在表中显示现有记录,所以我使用 jTable。我在网上找到了一些代码并对其进行了修改以提取记录并将它们显示在 jtable 中,但我不知道如何编写右键单击代码并显示弹出菜单。

在该弹出菜单中,我想显示删除记录和修改记录等选项。

这是我正在使用制作 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 新手,所以请善待您的回复。提前感谢大家的任何帮助!

4

4 回答 4

43

这是有关如何执行此操作的示例。实现这一点的最简单方法是JPopupMenu直接在 JTable 上设置一个。

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();
            }
        });
    }
}

如果您想自动选择进行右键单击的行,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

            }
        });
于 2013-05-24T22:13:06.180 回答
18

JTable 的一个问题是右键单击不会更改行选择。因此,如果您有一个适用于特定行的操作,您需要先左键单击该行,然后再右键单击以显示弹出菜单。

如果您希望在右键单击的位置选择该行,则可以使用如下代码:

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 );
    }
}
于 2013-05-24T22:44:58.063 回答
0

不幸的是,这些解决方案都不适用于 Mac 和 PC。不知道为什么。但这对两者都有效:

@Override
public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
    int row = table.rowAtPoint(SwingUtilities.convertPoint(popup, 0, 0, table));

    if (row > -1)
        table.setRowSelectionInterval(row, row);
}

我的解决方案的主要问题是,在用户选择其中一个菜单选项之前,它不会显示该行已被选中。

于 2022-01-18T05:25:59.773 回答
-2

另一个问题是上下文菜单是动态的,您的解决方案不处理根据单击的行更改菜单

popupMenu.addPopupMenuListener(new PopupMenuListener() 
{
   @Override
   public void popupMenuWillBecomeVisible(PopupMenuEvent e) 
   { 
       int rowAtPoint = table.rowAtPoint(SwingUtilities.convertPoint(popupMenu, new Point(0, 0), table));
       generateTablePopupMenu(rowAtPoint); // here
       SwingUtilities.invokeLater(new Runnable() 
           ...
于 2016-09-27T07:31:34.323 回答