如何通过对话框从另一个文件读取文本字段值？

Question

我的软件包中有两个文件： GUI.java 和 Dialog.java

GUI有两个文本字段和一个按钮。当我按下该按钮时，对话框变为可见。对话框中还有另一个按钮，用于将文本字段的值保存到.ini文件中。问题来了，它不保存更新的值，而是保存程序首次启动时存在的值。

在Google上进行了一些搜索之后，我发现我需要使用“动作监听器”，但是似乎根本无法正确使用它。

GUI.java：

import java.io.File;
import java.io.IOException;
import org.ini4j.Wini;

public class GUI extends javax.swing.JFrame {
    public GUI(){
        initComponents();
    }
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        textField1 = new javax.swing.JTextField();
        textField2 = new javax.swing.JTextField();
        openDialog = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        textField1.setText("1");

        textField2.setText("2");

        openDialog.setText("Open Dialog");
        openDialog.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                openDialogActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(openDialog, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(textField2, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(textField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(openDialog)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void openDialogActionPerformed(java.awt.event.ActionEvent evt) {                                           
         Dialog dialog = new Dialog(new javax.swing.JFrame(), true);
         dialog.addWindowListener(new java.awt.event.WindowAdapter() {
             @Override
             public void windowClosing(java.awt.event.WindowEvent e) {
                 dialog.setVisible(false);
             }
         });
         dialog.setVisible(true);
    }                                          

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new GUI().setVisible(true);
            }
        });
    }

    void save(int i){
        try {
            Wini ini = new Wini(new File("C:/Users/Paul/Desktop/Configs.ini"));
            int firstValue = Integer.parseInt(textField1.getText());
            int secondValue = Integer.parseInt(textField2.getText());
            ini.put("Configuration " + i, "First Value", firstValue);
            ini.put("Configuration " + i, "Second Value", secondValue);
            ini.store();
        } 
        catch (IOException ex) {}
    }
    private javax.swing.JButton openDialog;
    private javax.swing.JTextField textField1;
    private javax.swing.JTextField textField2;                   
}

Dialog.java：

public class Dialog extends javax.swing.JDialog {
    GUI GUI = new GUI();
    public Dialog(java.awt.Frame parent, boolean modal) {
        super(parent, modal);
        initComponents();
    }
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        save = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

        save.setText("Save");
        save.addActionListener(new java.awt.event.ActionListener() {
            @Override
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                saveActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(save)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(save)
                .addContainerGap())
        );

        pack();
    }// </editor-fold>                        

    private void saveActionPerformed(java.awt.event.ActionEvent evt) {                                     
        GUI.save(1);
    }                                    

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                Dialog dialog = new Dialog(new javax.swing.JFrame(), true);
                dialog.addWindowListener(new java.awt.event.WindowAdapter() {
                    @Override
                    public void windowClosing(java.awt.event.WindowEvent e) {
                        System.exit(0);
                    }
                });
                dialog.setVisible(true);
            }
        });
    }
    private javax.swing.JButton save;                 
}

Answer 1

Dialog不应创建GUI的新实例，在屏幕上显示的实例与Dialog所使用的实例之间没有任何关系。

相反，GUI应该将自身的引用传递给Dialog

public class Dialog extends javax.swing.JDialog {

    private GUI gui;

    public Dialog(GUI parent) {
        super(parent, true);
        this.gui = gui;
        initComponents();
    }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        save = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

        save.setText("Save");
        save.addActionListener(new java.awt.event.ActionListener() {
            @Override
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                saveActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
                        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                                                        .addContainerGap()
                                                        .addComponent(save)
                                                        .addContainerGap())
        );
        layout.setVerticalGroup(
                        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                        .addGroup(layout.createSequentialGroup()
                                                        .addContainerGap()
                                                        .addComponent(save)
                                                        .addContainerGap())
        );

        pack();
    }// </editor-fold>                        

    private void saveActionPerformed(java.awt.event.ActionEvent evt) {
        gui.save(1);
    }

    private javax.swing.JButton save;
}

这是非常基本的Java，在着手进行GUI开发之类的复杂操作之前，您应该熟悉一下。有关更多详细信息，请参见Passing Information to a Method or a Constructor

您的GUI类可能看起来像...

public class GUI extends javax.swing.JFrame {

    public GUI() {
        initComponents();
    }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        textField1 = new javax.swing.JTextField();
        textField2 = new javax.swing.JTextField();
        openDialog = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        textField1.setText("1");

        textField2.setText("2");

        openDialog.setText("Open Dialog");
        openDialog.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                openDialogActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
                        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                        .addGroup(layout.createSequentialGroup()
                                                        .addContainerGap()
                                                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                                                        .addComponent(openDialog, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                                                                        .addGroup(layout.createSequentialGroup()
                                                                                        .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                                                                                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                                                                                        .addComponent(textField2, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)))
                                                        .addContainerGap())
        );
        layout.setVerticalGroup(
                        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                        .addGroup(layout.createSequentialGroup()
                                                        .addContainerGap()
                                                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                                                                        .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                                                                        .addComponent(textField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                                                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                                        .addComponent(openDialog)
                                                        .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void openDialogActionPerformed(java.awt.event.ActionEvent evt) {
        Dialog dialog = new Dialog(this);
        dialog.setVisible(true);
    }

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new GUI().setVisible(true);
            }
        });
    }

    void save(int i) {
        // Code I can't execute
        // Also, don't ignore the exception, you should probably
        // rethrow it...
    }

    private javax.swing.JButton openDialog;
    private javax.swing.JTextField textField1;
    private javax.swing.JTextField textField2;
}

尽管，我认为如果要GUI保存数据，它应该检查对话框的结果，而不是将自身暴露于可能的虐待之下（removeAll ？）。在这种情况下，我会考虑使用JOptionPane

有关更多详细信息，请参见How to Make Dialogs。

此外，您越早放弃表单编辑器，您就会越好

  

我会很期待，看看是否可以通过JOptionPane使它工作

private void openDialogActionPerformed(java.awt.event.ActionEvent evt) {
    int response = JOptionPane.showOptionDialog(this, "Do you wish to save", "Save", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, null, null, null);
    if (response == JOptionPane.YES_OPTION) {
        save(1);
    }
}