退出菜单使用ActionListener不起作用

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英文:

Exit Menu using ActionListener doesn't work

问题

import java.awt.*;
import java.awt.event.*;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.ButtonGroup;
import javax.swing.JMenuBar;
import javax.swing.KeyStroke;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JScrollPane;
import javax.swing.JFrame;

public class testCoinSorterGUI extends testCoinSorter {

    JTextArea output;
    JScrollPane scrollPane;

    public JMenuBar createMenuBar() {
        JMenuBar menuBar;
        JMenu menu, submenu;
        JMenuItem menuItem;
        JRadioButtonMenuItem rbMenuItem;
        JCheckBoxMenuItem cbMenuItem;

        // Create the menu bar.
        menuBar = new JMenuBar();

        // Build the first menu.
        menu = new JMenu("Calculator");
        menu.setMnemonic(KeyEvent.VK_A);
        menu.getAccessibleContext().setAccessibleDescription(
                "The only menu in this program that has menu items");
        menuBar.add(menu);

        menuItem = new JMenuItem("Coin calculator");
        menu.add(menuItem);

        menuItem = new JMenuItem("Multi Coin calculator");
        menu.add(menuItem);

        // Build second menu in the menu bar.
        menu = new JMenu("Print coin list");
        menu.setMnemonic(KeyEvent.VK_N);
        menu.getAccessibleContext().setAccessibleDescription("This menu does nothing");
        menuBar.add(menu);

        // Build third menu in the menu bar.
        menu = new JMenu("Set details");
        menuBar.add(menu);

        menuItem = new JMenuItem("Set currency");
        menu.add(menuItem);

        menuItem = new JMenuItem("Set minimum coin input value");
        menu.add(menuItem);

        menuItem = new JMenuItem("Set maximum coin input value");
        menu.add(menuItem);
        menu.addSeparator();

        menuItem = new JMenuItem("Display program configurations");
        menu.add(menuItem);

        // Build fifth menu in the menu bar.
        menu = new JMenu("Quit the program");
        menuBar.add(menu);
        menu.addActionListener(
            new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    System.exit(0);
                }
            }
        );

        return menuBar;
    }

    public Container createContentPane() {
        // Create the content-pane-to-be.
        JPanel contentPane = new JPanel(new BorderLayout());
        contentPane.setOpaque(true);

        // Create a scrolled text area.
        output = new JTextArea(5, 30);
        output.setEditable(false);
        scrollPane = new JScrollPane(output);

        // Add the text area to the content pane.
        contentPane.add(scrollPane, BorderLayout.CENTER);

        return contentPane;
    }

    /** Returns an ImageIcon, or null if the path was invalid. */
    protected static ImageIcon createImageIcon(String path) {
        java.net.URL imgURL = testCoinSorterGUI.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        // Create and set up the window.
        JFrame frame = new JFrame("*** CoinSorterGUI ***");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Create and set up the content pane.
        testCoinSorterGUI demo = new testCoinSorterGUI();
        frame.setJMenuBar(demo.createMenuBar());
        frame.setContentPane(demo.createContentPane());

        // Display the window.
        frame.setSize(680, 480);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        // Schedule a job for the event-dispatching thread:
        // creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

Note: The provided code is a translation of the code you provided into Chinese. Please use this translation as needed. If you have any further questions or need assistance, feel free to ask.

英文:

I'm trying to exit menu using the ActionListener, however my code doesn't work properly and the "Quit the Program" button doesn't do anything. Below is the code:

 import java.awt.*;
import java.awt.event.*;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.ButtonGroup;
import javax.swing.JMenuBar;
import javax.swing.KeyStroke;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JScrollPane;
import javax.swing.JFrame;
public class testCoinSorterGUI extends testCoinSorter{
JTextArea output;
JScrollPane scrollPane;
public JMenuBar createMenuBar() {
JMenuBar menuBar;
JMenu menu, submenu;
JMenuItem menuItem;
JRadioButtonMenuItem rbMenuItem;
JCheckBoxMenuItem cbMenuItem;
//Create the menu bar.
menuBar = new JMenuBar();
//Build the first menu.
menu = new JMenu("Calculator");
menu.setMnemonic(KeyEvent.VK_A);
menu.getAccessibleContext().setAccessibleDescription(
"The only menu in this program that has menu items");
menuBar.add(menu);
menuItem = new JMenuItem("Coin calculator");
menu.add(menuItem);
menuItem = new JMenuItem("Multi Coin calculator");
menu.add(menuItem);
//Build second menu in the menu bar.
menu = new JMenu("Print coin list");
menu.setMnemonic(KeyEvent.VK_N);
menu.getAccessibleContext().setAccessibleDescription("This menu does nothing");
menuBar.add(menu);
//Build third menu in the menu bar.
menu = new JMenu("Set details");
menuBar.add(menu);
menuItem = new JMenuItem("Set currency");
menu.add(menuItem);
menuItem = new JMenuItem("Set minimum coin input value");
menu.add(menuItem);
menuItem = new JMenuItem("Set maximum coin input value");
menu.add(menuItem);
menu.addSeparator();
menuItem = new JMenuItem("Display program configurations");
menu.add(menuItem);
//Build fifth menu in the menu bar.
menu = new JMenu("Quit the program");
menuBar.add(menu);
menu.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
);
return menuBar;
}
public Container createContentPane() {
//Create the content-pane-to-be.
JPanel contentPane = new JPanel(new BorderLayout());
contentPane.setOpaque(true);
//Create a scrolled text area.
output = new JTextArea(5, 30);
output.setEditable(false);
scrollPane = new JScrollPane(output);
//Add the text area to the content pane.
contentPane.add(scrollPane, BorderLayout.CENTER);
return contentPane;
}
/** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = testCoinSorterGUI.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}
/**
* Create the GUI and show it.  For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("*** CoinSorterGUI ***");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
testCoinSorterGUI demo = new testCoinSorterGUI();
frame.setJMenuBar(demo.createMenuBar());
frame.setContentPane(demo.createContentPane());
//Display the window.
frame.setSize(680, 480);
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}

Currently I only want to test the "quit the program" button, so please ignore all the other menu.
Any help would be appreciated, I am really stucked though I think I have put the code in the correct order.

答案1

得分: 0

使用菜单项,而不是菜单

menu = new JMenu("退出程序");
menuBar.add(menu);
menu.addActionListener(

应该改为

JMenuItem menuI = new JMenuItem("退出程序");
menuBar.add(menuI);
menuI.addActionListener(
英文:

Use a menuitem, not a menu

menu = new JMenu("Quit the program");
menuBar.add(menu);
menu.addActionListener(

Should be

JMenuItem menuI = new JMenuItem("Quit the program");
menuBar.add(menuI);
menuI.addActionListener(

答案2

得分: 0

首先:

public class TestCoinSorterGUI extends TestCoinSorter{

类名应以大写字符开头,遵循JDK使用的约定。

我正试图使用ActionListener退出菜单

JMenuBar 用于显示 JMenu 对象。

JMenu 用于被点击并显示 JMenuItem 列表。

ActionListener 仅在 JMenuItem 上工作。

因此,代码的逻辑结构应为:

  • JMenuBar
    • JMenu
      • JMenuItem

当添加 JMenuItem 时,您可以为菜单项添加一个“加速键”,以便可以直接从键盘关闭应用程序。这样可以避免用户一直使用鼠标,而不必频繁点击菜单和菜单项。

英文:

First of all:

public class testCoinSorterGUI extends testCoinSorter{

Class names should start with an upper case character. Follow the conventions used by the JDK.

> I'm trying to exit menu using the ActionListener

A JMenuBar is designed to display JMenu objects.

A JMenu is designed to be clicked and display a list of JMenuItems.

An ActionListener only works on a JMenuItem.

So the logical structure of your code should be:

  • JMenuBar
    • JMenu
      • JMenuItem

When you add the JMenuItem you can add an "accelerator" to the menu item so the application by be closed directly from the keyboard. This save the user from using the mouse all the time and having to click on the menu and menu item.

huangapple
  • 本文由 发表于 2020年10月5日 06:26:03
  • 转载请务必保留本文链接:https://go.coder-hub.com/64200462.html
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