字符串文本未显示在Java中的附录文本中

Question

我正在Netbeans Java进行猜测。将猜测号与目标编号进行比较后，结果（消息/字符串文本）未显示在反馈面板TextArea中。我使用附录文本将文本从大型机类传递给了反馈类别。但是，按下猜测按钮后，文本未显示在反馈中。请帮我。

mainfame.java

public class MainFrame extends JFrame{
    FeedbackPanel formPanel;
    InputPanel textPanel;
    public static int target;
    JTextArea ta;
    
    public MainFrame()
    {
    super("HIgher-Lower Game");
        
    formPanel=new FeedbackPanel();
    add(formPanel, BorderLayout.EAST);
       
        textPanel=new InputPanel();
        add(textPanel, BorderLayout.WEST);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       

        formPanel.setFormListener(new FormListener(){
            public void formEventOccurred(FormEvent e){
                int num = e.getNum();
                //int square=num*num;
                if (num == target)
                    {
                       formPanel.appendText("Congratulations, your guess is correct!");
                        //formPanel.setText("Congratulations, your guess is correct!");
                        //ta.setText("Congratulations, your guess is correct!");
                        //System.out.paMairintln("Congratulations, your guess is correct!");
                    }
                else if (num > target)
                    //if guess is higher than the target
                    {
                        formPanel.appendText("Your guess is higher than the target");
                        //formPanel.setText("Your guess is higher than the target");
                        //ta.setText("Your guess is higher than the target");
                        //System.out.println("Your guess is higher than the target");
                    }
                else if (num < target)
                    //if guess is lower than the target
                    {
                        formPanel.appendText("Your guess is lower than the target");
                        //formPanel.setText("Your guess is lower than the target");
                        //ta.setText("Your guess is lower than the target");
                        //System.out.println("Your guess is lower than the target");
                    }
                //textPanel.appendText(Integer.toString(square));
            } 
        });
        
        textPanel=new InputPanel();
        add(textPanel, BorderLayout.WEST);
                
        setSize(300,300);
    setVisible(true);
    this.pack();
    
    }
     
    public static void main(String[] args) {
        Random random = new Random();
        target = random.nextInt(100);
         
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
        new MainFrame();
            }
    });
    }
}

inputpanel.java

public class InputPanel extends JPanel {
    private JLabel label1;
    private JTextField tfIn;
    private JButton b;
    
    private FormListener formListener;

    public FormListener getTextListener() {
        return formListener;
    }

    public void setFormListener(FormListener formListener) {
        this.formListener = formListener;
    }

    public InputPanel() {
        GridBagLayout gb=new GridBagLayout();
        GridBagConstraints gbc=new GridBagConstraints();
        gbc.insets=new Insets(5,5,5,5);
        setLayout(gb);
        setBorder(BorderFactory.createTitledBorder("InputForm"));
        
        label1 = new JLabel ("Enter number [1-100]");
        gbc.anchor=GridBagConstraints.FIRST_LINE_END;
        gbc.gridx=1;
        gbc.gridy=1;
        gbc.gridheight=1;
        gbc.gridwidth=1;
        add(label1,gbc);
        
        tfIn = new JTextField (10);
        gbc.gridx=1;
        gbc.gridy=2;
        gbc.gridheight=1;
        gbc.gridwidth=1;
        add(tfIn,gbc);
        
        b = new JButton ("Guess");
        gbc.anchor=GridBagConstraints.CENTER;
        gbc.gridx=1;
        gbc.gridy=3;
        gbc.gridheight=1;
        gbc.gridwidth=2;
        add(b,gbc);
        
        b.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                int num = Integer.parseInt(tfIn.getText());
                FormEvent ev=new FormEvent(this,num);
                if(formListener != null){
                    formListener.formEventOccurred(ev);
                }
            }
            
        });
    }
}

feffbackpanel.java

public class FeedbackPanel extends JPanel{
    JTextArea ta;

    FormListener listen;
        
    public FeedbackPanel(){
        setBorder(BorderFactory.createTitledBorder("Feedback"));
        setLayout(new BorderLayout());
        ta=new JTextArea(5,20);
        
        
        add(new JScrollPane(ta), BorderLayout.CENTER);
    }
    
    public void appendText(String text){
        ta.append(text + "\n" + "\r");
    
    }

    public void setFormListener(FormListener formListener) {
        this.listen = formListener;
    }




 
}

formevent.java.java

public class FormEvent extends EventObject{
    private int num;

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }
    
    public FormEvent(Object source){
        super(source);
    }
    
    public FormEvent(Object source, int num){
        super(source);
        this.num=num;
    }
}

formlistener.java

public interface FormListener extends EventListener{
    public void formEventOccurred(FormEvent e); 
    
}

Answer 1

您的代码中的问题：

＃1是，大型机中的formeventoccurred（）从未被调用。
发生这个问题，因为有两个面板，它们将相互通信。您通过创建一个界面来解决此问题，这是正确的。但是，错误类的接口被调用。

＃2是，您创建并添加了两次TextPanel。这不应引起所描述的问题，但这不是很好。

＃3是，变量的命名不好。请看一下命名约定。此代码不容易阅读。

＃4并不是真正的问题，但是如果不需要，则不应使用关键字静态。

＃5是，如果可以是本地变量，则原始数据类型和对象不应将其声明为类属性（字段）。对于可读性而言，这要好得多。

＃6是，代码中有很多冗余。如果程序员在阅读自己的代码方面有问题，可能会发生这种情况。如果是这种情况，那不是直接“不好”，这对初学者来说是正常的。下次，尝试通过使用变量名称“告诉他们的工作是什么”，等等。

＃7是，通常，将变量“私有”是一种好习惯使它们公开或受到保护，等等。

现在，通过学习来乐趣！

工作代码：

这是工作代码的完整版本：

类：Mainframe

public class MainFrame extends JFrame {

    private int numberToGuess;

    public MainFrame() {
        /* general things */
        numberToGuess = new Random().nextInt(100);

        /* feedbackPanel */
        FeedbackPanel feedbackPanel = new FeedbackPanel();
        add(feedbackPanel, BorderLayout.EAST);

        /* inputPanel */
        InputPanel inputPanel = new InputPanel();
        inputPanel.setFormListener(new FormListener() {
            @Override
            public void formEventOccurred(FormEvent e) {
                int guessedNumber = e.getNum();
                if (guessedNumber == numberToGuess) {
                    feedbackPanel.appendText("Congratulations, your guess is correct!");
                } else if (guessedNumber > numberToGuess) {
                    feedbackPanel.appendText("Your guess is higher than the target");
                } else if (guessedNumber < numberToGuess) {
                    feedbackPanel.appendText("Your guess is lower than the target");
                }
            }
        });
        add(inputPanel, BorderLayout.WEST);

        /* frame settings */
        setTitle("Higher-Lower Game");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 300);
        setVisible(true);
        this.pack();
    }

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

}

类：feffbackpanel

public class FeedbackPanel extends JPanel {

    private JTextArea textArea;

    public FeedbackPanel() {
        setBorder(BorderFactory.createTitledBorder("Feedback"));
        setLayout(new BorderLayout());
        textArea = new JTextArea(5, 20);
        add(new JScrollPane(textArea), BorderLayout.CENTER);
    }

    public void appendText(String text) {
        textArea.append(text + "\n" + "\r");
    }

}

class：inputpanel

public class InputPanel extends JPanel {

    private JLabel label1;
    private JTextField tfIn;
    private JButton button;
    private FormListener formListener;

    public InputPanel() {
        GridBagLayout gb = new GridBagLayout();
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(5, 5, 5, 5);
        setLayout(gb);
        setBorder(BorderFactory.createTitledBorder("InputForm"));

        label1 = new JLabel("Enter number [1-100]");
        gbc.anchor = GridBagConstraints.FIRST_LINE_END;
        gbc.gridx = 1;
        gbc.gridy = 1;
        gbc.gridheight = 1;
        gbc.gridwidth = 1;
        add(label1, gbc);

        tfIn = new JTextField(10);
        gbc.gridx = 1;
        gbc.gridy = 2;
        gbc.gridheight = 1;
        gbc.gridwidth = 1;
        add(tfIn, gbc);

        button = new JButton("Guess");
        gbc.anchor = GridBagConstraints.CENTER;
        gbc.gridx = 1;
        gbc.gridy = 3;
        gbc.gridheight = 1;
        gbc.gridwidth = 2;
        add(button, gbc);

        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int num = Integer.parseInt(tfIn.getText());
                FormEvent ev = new FormEvent(this, num);
                if (formListener != null) {
                    formListener.formEventOccurred(ev);
                }
            }

        });
    }

    public void setFormListener(FormListener formListener) {
        this.formListener = formListener;
    }
}

类：formevent

public class FormEvent extends EventObject {

    private int num;

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    public FormEvent(Object source) {
        super(source);
    }

    public FormEvent(Object source, int num) {
        super(source);
        this.num = num;
    }
}

接口：formListener

public interface FormListener extends EventListener {

    public void formEventOccurred(FormEvent e);

}