JPopupMenu 菜单未出现

Question

这是我的 JPopupMenu 的代码以及我如何添加它，当我右键单击 table:

时它应该会响应

    JMenuItem deleteRows = new JMenuItem("Delete Row");
    popup.add(deleteRows);

    personTable.addMouseListener(new MouseAdapter() {

        @Override
        public void mousePressed(MouseEvent e) {
            if(e.getButton() == MouseEvent.BUTTON3) {
                popup.show(personTable, e.getX(), e.getY());
            }
        }

    });

我不确定为什么在应用程序中右键单击 table 时没有出现弹出菜单。如果有人告诉我我做错了什么，我将不胜感激。

Answer 1

不同的 OS 弹出窗口的触发器是不同的，你不能简单地使用 mousePressed 并且你当然不应该使用 e.getButton() == MouseEvent.BUTTON3

来自How to use Menus, Bringing up a PopupMenu

The exact gesture that should bring up a popup menu varies by look and feel. In Microsoft Windows, the user by convention brings up a popup menu by releasing the right mouse button while the cursor is over a component that is popup-enabled. In the Java look and feel, the customary trigger is either pressing the right mouse button (for a popup that goes away when the button is released) or clicking it (for a popup that stays up).

相反，您应该检查每个鼠标事件，pressed、released 和 clicked。您还应该使用 MouseEvent#isPopupTrigger 来确定该事件是否是 OS.

的弹出触发器

说了那么多，只有我们 JComponent#setComponentPopupMenu 让它自己决定会更简单

personTable.setComponentPopupMenu(popup);

可运行示例...

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.table.DefaultTableModel;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                DefaultTableModel model = new DefaultTableModel(10, 10);
                JTable table = new JTable(model);

                JMenuItem mi = new JMenuItem("I'll be your menu for today");
                JPopupMenu popup = new JPopupMenu();
                popup.add(mi);

                table.setComponentPopupMenu(popup);

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new JScrollPane(table));
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

}

Answer 2

下面是不使用鼠标侦听器创建弹出菜单的简单方法：

JpopupMenu popMenu = new JpopupMenu() ;
JMenuItem item = new  JMenuItem("my item") ;
popMenu.add(item);
myTable.setComponentPopupMenu(popMenu);

JPopupMenu 菜单未出现

JPopupMenu Menu Not Appearing

java

swing

jtable

jpopupmenu

可运行示例...