对Swing单选按钮Applet进行故障诊断

时间:2013-08-12 02:03:56

标签: java swing applet radio

我必须为学校作业创建一个Swing applet,并获得一个链接(http://java.sun.com/docs/books/tutorial/uiswing/components/index.html)来查看各种Swing教程,并使用其中一个来创建一个独特的Java applet。我选择按照如何使用单选按钮教程的代码。我仔细阅读了代码并在更改内容时将其输入,以便它们与我的图片相匹配。我的代码是

package components;

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

public class OSButtons extends JPanel implements ActionListener {

    static String windowsString = "Windows";
    static String linuxString = "Linux";
    static String macString = "Mac";

    JLabel picture;

    public OSButtons() {
        super(new BorderLayout());

        JRadioButton windowsButton = new JRadioButton(windowsString);
        windowsButton.setMnemonic(KeyEvent.VK_W);
        windowsButton.setActionCommand(windowsString);
        windowsButton.setSelected(true);

        JRadioButton linuxButton = new JRadioButton(linuxString);
        linuxButton.setMnemonic(KeyEvent.VK_L);
        linuxButton.setActionCommand(linuxString);

        JRadioButton macButton = new JRadioButton(macString);
        macButton.setMnemonic(KeyEvent.VK_M);
        macButton.setActionCommand(macString);

        ButtonGroup group = new ButtonGroup();
        group.add(windowsButton);
        group.add(linuxButton);
        group.add(macButton);

        windowsButton.addActionListener(this);
        linuxButton.addActionListener(this);
        macButton.addActionListener(this);

        picture = new JLabel(createImageIcon("images/" + windowsString + ".gif"));
        picture.setPreferredSize(new Dimension(200, 150));

        JPanel radioPanel = new JPanel(new GridLayout(0, 1));
        radioPanel.add(windowsButton);
        radioPanel.add(linuxButton);
        radioPanel.add(macButton);

        add(radioPanel, BorderLayout.LINE_START);
        add(picture, BorderLayout.CENTER);
        setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
    }

    public void actionPerformed(ActionEvent e) {
        picture.setIcon(createImageIcon("images/" + e.getActionCommand() + ".gif"));
    }

    protected static ImageIcon createImageIcon(String path) {
        java.net.URL imgURL = OSButtons.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }

    private static void createAndShowGUI() {
        JFrame frame = new JFrame("OSButtons");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JComponent newContentPane = new RadioButtonDemo();
        newContentPane.setOpaque(true);
        frame.setContentPane(newContentPane);

        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

我希望这是可读的。无论如何,我编译了代码,它出现了这些错误:

enter image description here

我真的不知道如何从这里开始修复这些,这个任务有点被抛到我身上,我不得不完全靠自己研究Swing,SWT和AWT。我们将非常感谢您提供的任何帮助。

1 个答案:

答案 0 :(得分:1)

更改...

picture = newJLabel(createImageIcon("images/"+ windowsString + ".gif"));

为...

picture = new JLabel(createImageIcon("images/"+ windowsString + ".gif"));

更改

radiopanel.add(macButton);

为...

radioPanel.add(macButton);

Java是大小写敏感,变量名称大小写必须匹配

此...

JComponent newContentPane = new RadioButtonDemo();

我怀疑是复制/粘贴错误。您更改了原始代码的class名称,但忘记更改对它的任何引用。

...试

JComponent newContentPane = new OSButtons();

相反

<强>更新

好。我们假设您的源文件位于C:\Users\Keith\Desktop\components

在命令提示符下,您可以使用类似......

之类的东西来编译它们
C:\> cd C:\Users\Keith\Desktop
C:\Users\Keith\Desktop> javac components.OSButtons.java
C:\Users\Keith\Desktop> java components.OSButtons

包名和类文件的预期目录之间存在直接联盟。