Java JMenu 无法正常工作

Question

我一直在研究一个 html 文本编辑程序，我想知道是否有人可以帮助我解决这个小问题。我有两个 jmenus，但其中一个行为不端。我有两个问题。 1 菜单中的菜单项虽然不是子菜单，但有一个子菜单箭头

1. 是我向菜单添加了一个 Action 监听器，但是当我单击该 Action 时，该 Action 并没有发生。这是代码。

   import java.awt.GridLayout;
   import java.awt.event.ActionEvent;
   import java.awt.event.ActionListener;
   import java.awt.event.KeyEvent;
   import java.io.File;
   import java.io.FileReader;
   import java.io.FileWriter;
   import java.io.IOException;
   
   import javax.swing.JButton;
   import javax.swing.JFileChooser;
   import javax.swing.JFrame;
   import javax.swing.JMenu;
   import javax.swing.JMenuBar;
   import javax.swing.JMenuItem;
   import javax.swing.JOptionPane;
   import javax.swing.JTextArea;
   
   
   public class Window {
   
   static boolean saved = false;
   static boolean opened = false;
   static File saveDirectory = null;
   static File openDirectory = null;
   
   static final JTextArea editor = new JTextArea(10,50);
   
   public static void openWindowEditor(){
   JFrame f = new JFrame("Easy HTML Text editor");
   
   JMenuBar menuBar = new JMenuBar();
   
   JMenu fileMenu = new JMenu("File");
   
   JMenu viewMenu = new JMenu("View");
   
   JMenuItem fileMenuSave = new JMenuItem("Save");
   JMenuItem fileMenuOpen = new JMenuItem("Open");
   JMenuItem fileMenuSaveAs = new JMenuItem("Save as...");
   
   JMenuItem viewMenuEasyInsert = new JMenu("Easy insert");
   
   fileMenu.setMnemonic(KeyEvent.VK_A);
   
   viewMenu.setMnemonic(KeyEvent.VK_A);
   
   menuBar.add(fileMenu);
   menuBar.add(viewMenu);
   
   fileMenu.add(fileMenuSave);
   fileMenu.add(fileMenuOpen);
   fileMenu.add(fileMenuSaveAs);
   
   viewMenu.add(viewMenuEasyInsert);
   
   fileMenuSave.addActionListener(new ActionListener() {
       public void actionPerformed(ActionEvent arg0) {
           save(editor.getText());
       }
   });
   
   fileMenuOpen.addActionListener(new ActionListener() {
       public void actionPerformed(ActionEvent arg0) {
           open();
       }
   });
   
   fileMenuSaveAs.addActionListener(new ActionListener() {
       public void actionPerformed(ActionEvent e) {
           saveAs();
       }
   });
   
   viewMenuEasyInsert.addActionListener(new ActionListener() {
       public void actionPerformed(ActionEvent arg0) {
           openEasyInsertWindow();
       }
   });
   
   f.setJMenuBar(menuBar);
   f.add(editor);
   
   f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
   f.setLayout(new GridLayout(1,1));
   f.pack();
   f.setVisible(true);
   }
   
   public static void open(){
   JFileChooser chooser = new JFileChooser();
   int returnVal = chooser.showDialog(null, "open");
   
   if(returnVal == JFileChooser.APPROVE_OPTION){
   File file = chooser.getSelectedFile();
   
   try{
   editor.read(new FileReader(file), null);
   }catch(IOException e){
       JOptionPane.showMessageDialog(null, e);
       }
   }
   }
   
   public static void save(String text){
   JFileChooser chooser = new JFileChooser();
   File file = null;
   
   int returnVal = chooser.showDialog(null, "Save");
   if(returnVal == JFileChooser.APPROVE_OPTION){
   file = (chooser.getSelectedFile());
   
   String result = text.replace("\n", System.getProperty("line.separator"));
   
   saveDirectory = chooser.getSelectedFile();
   try{
   FileWriter fw = new FileWriter(file);
   fw.write(result);
   fw.close();
   saved = true;
   }catch(IOException e){
       JOptionPane.showMessageDialog(null, e);
       }
   }
   }
   
   public static void saveAs(){
   JFileChooser chooser = new JFileChooser();
   File dir;
   
   int returnVal = chooser.showDialog(null, "Save as...");
   if(returnVal == JFileChooser.APPROVE_OPTION){
   dir = chooser.getSelectedFile();
   try{
       FileWriter fw = new FileWriter(dir);
       fw.write(editor.getText());
       fw.close();
   }catch(IOException e){
       JOptionPane.showMessageDialog(null, e);
       }
   }
   }
   
   public static void openEasyInsertWindow(){
   JFrame f = new JFrame("easy insert");
   
   JButton insertDivButton = new JButton("Insert <div> element");
   JButton openInsertSettings = new JButton("Open the insert settings");
   
   f.setLayout(new GridLayout(2,1));
   f.add(insertDivButton);
   f.add(openInsertSettings);
   
   f.pack();
   f.setVisible(true);
   
   JOptionPane.showMessageDialog(editor, "Easy insert");
   }
   }
   

Answer 1

因为您将其定义为 JMenu 而不是 JMenuItem

JMenuItem viewMenuEasyInsert = new JMenu("Easy insert");

应该是

JMenuItem viewMenuEasyInsert = new JMenuItem("Easy insert");