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Java 使用jpopmpmenu从JMenuItem获取JMenu_Java_Swing_Jmenu_Jmenuitem_Jpopupmenu - Fatal编程技术网

Java 使用jpopmpmenu从JMenuItem获取JMenu

Java 使用jpopmpmenu从JMenuItem获取JMenu,java,swing,jmenu,jmenuitem,jpopupmenu,Java,Swing,Jmenu,Jmenuitem,Jpopupmenu,我希望在使用JPopupMenu单击我的JMenuItem时获得jMenus的名称 我在每个JMenuItem上放置了一个名为“MenuContextureListener”的ActionListener: ActionListener menuContextuelListener = new ActionListener() { public void actionPerformed(ActionEvent event) { System.out.println(eve

我希望在使用JPopupMenu单击我的JMenuItem时获得jMenus的名称

我在每个JMenuItem上放置了一个名为“MenuContextureListener”的ActionListener:

ActionListener menuContextuelListener = new ActionListener() {
    public void actionPerformed(ActionEvent event) {
        System.out.println(event.getActionCommand());
    }
};
如何从选中的JMenuItem中获取JMenu父项的名称

我也在同一个侦听器中尝试了这种方法,但不起作用:

JMenuItem jmi = (JMenuItem) event.getSource();
JPopupMenu jpm = (JPopupMenu) jmi.getParent();
JMenu menu = (JMenu) jpm.getInvoker();
这张照片来自:

侦听器的完整代码:

ActionListener menuContextuelListener = new ActionListener(){
             public void actionPerformed(ActionEvent event)
              {

                     JMenuItem source = (JMenuItem)(event.getSource());
                        try{
                            JMenuItem menuItem = (JMenuItem) event.getSource(); 
                            JPopupMenu popupMenu = (JPopupMenu) menuItem.getParent(); 
                            Component invoker = popupMenu.getInvoker();      
                            JPopupMenu popup = (JPopupMenu) invoker.getParent();
                            System.out.println("NAME OF JMENU: "+popup.getName());

                        }catch(Exception ex){
                            ex.printStackTrace();
                        }
              }
        };
下面是菜单构造的示例(动态):

我用下面的代码检查。。。我可以看到JMenu的名称:

System.out.println(tJMenu.get(tJMenu.size()-1).getName());
您在论坛中找到了关于如何执行此操作的建议,为什么要更改找到的代码

快速浏览一下,您的代码中有一个额外的getParent()语句

调用程序将是JMenu。不需要第二条getParent()语句

下面是一些更通用的代码,允许您获取菜单项和子菜单项的JMenu:

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

public class MenuItemAction implements ActionListener
{
    public void actionPerformed(ActionEvent e)
    {
        JMenuItem mi = (JMenuItem)e.getSource();
        mi.setText(mi.getText() + "0");
        JMenu menu = getMenuBarMenu(mi);
        System.out.println("Menu: " + menu.getText());

        JFrame frame = (JFrame)SwingUtilities.windowForComponent(menu);
        System.out.println("Frame: " + frame.getTitle());
    }

    private JMenu getMenuBarMenu(JMenuItem item)
    {
        JMenu menu = null;

        while (menu == null)
        {
            JPopupMenu popup = (JPopupMenu)item.getParent();
            item = (JMenuItem)popup.getInvoker();

            if (! (item.getParent() instanceof JPopupMenu) )
                menu = (JMenu)item;
        }

        return menu;
    }


    private static void createAndShowGUI()
    {
        ActionListener listener = new MenuItemAction();

        // Create menu bar

        JMenuBar menuBar = new JMenuBar();

        JMenu menu = new JMenu( "File" );
        menuBar.add( menu );

        JMenuItem item1 = new JMenuItem("Item 1");
        menu.add( item1 );

        JMenu subMenu1 = new JMenu("SubMenu 1");
        menu.add( subMenu1 );

        JMenuItem subItem1 = new JMenuItem("SubItem 1");
        subMenu1.add( subItem1 );

        JMenu subMenu12 = new JMenu("SubMenu 12");
        subMenu1.add( subMenu12 );

        JMenuItem subItem12 = new JMenuItem("SubItem 12");
        subMenu12.add( subItem12 );

        item1.addActionListener( listener );
        subItem1.addActionListener( listener );
        subItem12.addActionListener( listener );

        JFrame frame = new JFrame("Get Menu and Frame");
        frame.setJMenuBar( menuBar );
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        frame.setSize(200, 200);
        frame.setLocationRelativeTo( null );
        frame.setVisible(true);
    }

    public static void main(String[] args)
    {
        EventQueue.invokeLater( () -> createAndShowGUI() );
/*
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowGUI();
            }
        });
*/
    }
}

将来当你提问时,请像我一样发布一个完整的答案,这样我们就可以准确地看到你在做什么。

是的,但它返回“NAME OF JMENU:null”。你的代码的哪一部分会打印这个?嗨,伯杰,请在下面的答案中找到代码。感谢您的支持。如果
getName
返回空值,请尝试使用自定义名称首先在菜单上调用
setName
。我将名称设置为“fMenu=newjmenu(“文件”);”。您认为我必须设置名称吗?谢谢您的回答和通用代码。它工作得很好。
System.out.println(tJMenu.get(tJMenu.size()-1).getName());
JMenuItem menuItem = (JMenuItem) event.getSource(); 
JPopupMenu popupMenu = (JPopupMenu) menuItem.getParent(); 
Component invoker = popupMenu.getInvoker();      
//JPopupMenu popup = (JPopupMenu) invoker.getParent(); // why did you add this?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MenuItemAction implements ActionListener
{
    public void actionPerformed(ActionEvent e)
    {
        JMenuItem mi = (JMenuItem)e.getSource();
        mi.setText(mi.getText() + "0");
        JMenu menu = getMenuBarMenu(mi);
        System.out.println("Menu: " + menu.getText());

        JFrame frame = (JFrame)SwingUtilities.windowForComponent(menu);
        System.out.println("Frame: " + frame.getTitle());
    }

    private JMenu getMenuBarMenu(JMenuItem item)
    {
        JMenu menu = null;

        while (menu == null)
        {
            JPopupMenu popup = (JPopupMenu)item.getParent();
            item = (JMenuItem)popup.getInvoker();

            if (! (item.getParent() instanceof JPopupMenu) )
                menu = (JMenu)item;
        }

        return menu;
    }


    private static void createAndShowGUI()
    {
        ActionListener listener = new MenuItemAction();

        // Create menu bar

        JMenuBar menuBar = new JMenuBar();

        JMenu menu = new JMenu( "File" );
        menuBar.add( menu );

        JMenuItem item1 = new JMenuItem("Item 1");
        menu.add( item1 );

        JMenu subMenu1 = new JMenu("SubMenu 1");
        menu.add( subMenu1 );

        JMenuItem subItem1 = new JMenuItem("SubItem 1");
        subMenu1.add( subItem1 );

        JMenu subMenu12 = new JMenu("SubMenu 12");
        subMenu1.add( subMenu12 );

        JMenuItem subItem12 = new JMenuItem("SubItem 12");
        subMenu12.add( subItem12 );

        item1.addActionListener( listener );
        subItem1.addActionListener( listener );
        subItem12.addActionListener( listener );

        JFrame frame = new JFrame("Get Menu and Frame");
        frame.setJMenuBar( menuBar );
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        frame.setSize(200, 200);
        frame.setLocationRelativeTo( null );
        frame.setVisible(true);
    }

    public static void main(String[] args)
    {
        EventQueue.invokeLater( () -> createAndShowGUI() );
/*
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowGUI();
            }
        });
*/
    }
}