GUI应用程序，用于接受来自文本字段的学生信息并将其显示在组合框中

Question

  

用户将输入全名，地址，城市，省份，邮政编码，   电话号码和电子邮件在文本字段控件中。

     

将选择学生的专业（计算机科学或商业）   从两个单选按钮。

     

组合框将随时显示每个程序的课程列表   用户选择所需的程序。课程将添加到列表中   每当用户从相应的组合中选择课程时，框就会出现   框。

     

确保用户无法多次添加课程。额外   有关学生的信息将通过一组支票提供   盒子（如参与各种活动等）。

     

有关学生的所有信息都将显示在文本区域中   成分

我的TextArea未显示在表单中。甚至信息也没有显示在textarea中。

我的代码如下：

//运行prog

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

//creating the main frame, and stick the other panels inside
public Test() 
{
    super("Student Information");
    JFrame frame = new JFrame("Student Information");
    BoxLayout bl = new BoxLayout(frame.getContentPane(),BoxLayout.Y_AXIS);
    FlowLayout fl = new FlowLayout(FlowLayout.LEFT);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLayout(bl);
    frame.setSize(800, 300);
    //frame.setPreferredSize(new Dimension(1200,700));
    panelTop = new JPanel();
    panelBot = new JPanel();
    panelTop.add(gridLayout(),  "Left to right");
    panelTop.add(midLayout(), "Left to right");
    //panelTop.add(comboLayout(), "Left to right");
    JPanel pane = new JPanel();
    model = new DefaultListModel<String>();
    courseList =  new JList<>(model);
    JScrollPane scrpn = new JScrollPane(courseList);
    pane.setLayout(new GridLayout(3,1));
    radioCS = new JRadioButton("Computer Science");
    radioBus = new JRadioButton("Business");
    radioCS.setSelected(true);
    ButtonGroup btngrp = new ButtonGroup();
    Person person = new Person();
    radioCS.addActionListener(person);
    radioBus.addActionListener(person);
    JPanel topPane = new JPanel();
    topPane.setLayout(new GridLayout(0, 2));
    JPanel innerPane = new JPanel();
    innerPane.setLayout(new GridLayout(2, 0));
    btngrp.add(radioCS);
    btngrp.add(radioBus);
    topPane.add(radioCS);
    topPane.add(radioBus);
    courseList.setSize(500,500);
    courseList.setPreferredSize(new Dimension(200,200));
    comboBox.addItemListener(new ItemListener()
            {
                @Override
                public void itemStateChanged(ItemEvent event) 
                {
                    if (event.getStateChange() == ItemEvent.SELECTED) 
                    {

                        if (!s.equals(comboBox.getSelectedItem().toString())) 
                        {

                            if (comboBox.getSelectedItem().toString().equals(options1[1]) && a == 0) {
                                a = 1;
                                model.addElement(comboBox.getSelectedItem().toString());
                                items += "\n" + comboBox.getSelectedItem().toString();
                            }
                            if (comboBox.getSelectedItem().toString().equals(options1[2]) && b == 0) {
                                b = 1;
                                model.addElement(comboBox.getSelectedItem().toString());
                                items += "\n" + comboBox.getSelectedItem().toString();
                            }
                            if (comboBox.getSelectedItem().toString().equals(options1[3]) && c == 0) {
                                c = 1;
                                model.addElement(comboBox.getSelectedItem().toString());
                                items += "\n" + comboBox.getSelectedItem().toString();
                            }
                            if (comboBox.getSelectedItem().toString().equals(options2[1]) && d == 0) {
                                d = 1;
                                model.addElement(comboBox.getSelectedItem().toString());
                                items += "\n" + comboBox.getSelectedItem().toString();
                            }
                            if (comboBox.getSelectedItem().toString().equals(options2[2]) && e == 0) {
                                e = 1;
                                model.addElement(comboBox.getSelectedItem().toString());
                                items += "\n" + comboBox.getSelectedItem().toString();
                            }

                        }
                    }

                }

            });
    innerPane.add(comboBox);
    innerPane.add(scrpn);
    pane.add(topPane);
    pane.add(innerPane);

    panelBot.add(botLayout(), "Left to right");
    submitBtn = new JButton("Submit");
    panelBot.add(submitBtn);
    frame.add(panelTop);
    frame.add(panelBot);
    frame.setLocationRelativeTo(null);
    frame.pack();
    frame.setVisible(true);

    // Set a size to the the JTextArea
    txtArea.setPreferredSize(new Dimension(400, 30));
    submitBtn.addActionListener(this);
}
//grid layout panel for label and textboxes section
public static JPanel gridLayout() {
    JPanel panel = new JPanel(new GridLayout(0, 2));
    panel.setSize(500, 500);
    panel.setPreferredSize(new Dimension(400, 400));
    Label labelArr[] = new Label[] { new Label("Name: "), new Label("Address: "), new Label("Province: "),
            new Label("City: "), new Label("Postal Code: "), new Label("Phone Number: "), new Label("Email: ") };

    nameField = new JTextField();
    addrField = new JTextField();
    provField = new JTextField();
    cityField = new JTextField();
    postField = new JTextField();
    phoneField = new JTextField();
    emailField = new JTextField();

    JTextField txtArr[] = new JTextField[] { nameField, addrField, provField, cityField, postField, phoneField,
            emailField };
    for (int i = 0; i < txtArr.length; i++) {
        panel.add(labelArr[i]);
        panel.add(txtArr[i]);
    }
    return panel;
}    public static JPanel midLayout() {
    JPanel panel = new JPanel(new FlowLayout());
    checkSC = new JCheckBox("Student Council");
    checkVW = new JCheckBox("Volunteer Work");
    panel.add(checkSC);
    panel.add(checkVW);
    return panel;
}
public static JPanel botLayout() 
{
    JPanel panel = new JPanel(new FlowLayout());
    // Add your txtArea inside a JScrollPane.
    panel.add(new JScrollPane(txtArea));
    return panel;
}
@Override
public void actionPerformed(ActionEvent e) 
{
    String name = nameField.getText();
    String addr = addrField.getText();
    String prov = provField.getText();
    String post = postField.getText();
    String phone = phoneField.getText();
    String email = emailField.getText();

    boolean isCS = radioCS.isSelected(); // If false then Business.
    boolean isCouncil = checkSC.isSelected();
    boolean isVolunteer = checkVW.isSelected();

    ArrayList<String> courses = new ArrayList<String>();
    for(int i=0; i<courseList.getModel().getSize(); i++) {
        courses.add(courseList.getModel().getElementAt(i));
    }

    txtArea.setText(name + " (" + phone + ") " + email + ". " + addr + ", " + prov + ", " + post+"\r\n");
    txtArea.append((isCS ? "Computer Science" : "Business")+". "+(isCouncil ? "Student Council, " : "")+(isVolunteer ? "Volunteer Work" : "")+". "+courses);
}
private class Person implements ActionListener 
{
    @Override
    public void actionPerformed(ActionEvent arg0) 
    {
        if (radioCS.isSelected()) {
            comboBox.setModel(comboBox1);
        }
        if (radioBus.isSelected()) {
            comboBox.setModel(comboBox2);
        }
    }
}

Answer 1

您要将txtArea添加到同一个面板两次。由于您先在botLayout()中添加，因此可以在panelBot.add(txtArea);方法中删除createAndShowGUI()。您的txtArea没有任何文本，并且不在JScrollPane中，因此不会出现任何内容。文本未添加到txtArea的原因是因为TextField在您输入时没有要监听的操作。您不希望在您的字段上使用侦听器，因为它会产生无意义的输出。根据您的描述，您的JTextFields，JRadioButtons，JCheckBoxes和JList需要在方法之外声明，以便可以在submitBtn侦听器中访问它们。从那里，您现在可以访问用户输入的内容并将其放在txtArea内。

// This is what is outside your methods alongside txtArea.
public static JTextArea txtArea = new JTextArea();
public static JTextField nameField, addrField, provField, cityField, postField, phoneField, emailField;
public static JRadioButton radioCS, radioBus;
public static JCheckBox checkSC, checkVW;
public static JList<String> courseList;

// This is what you need to change inside comboLayout()
radioCS = new JRadioButton("Computer Science");
radioBus = new JRadioButton("Business");
radioCS.setSelected(true);
ButtonGroup btngrp = new ButtonGroup();
JPanel topPane = new JPanel();
topPane.setLayout(new GridLayout(0, 2));
JPanel innerPane = new JPanel();
innerPane.setLayout(new GridLayout(2, 0));
btngrp.add(radioCS);
btngrp.add(radioBus);
topPane.add(radioCS);
topPane.add(radioBus);

// Changing midLayout()
public static JPanel midLayout() {
    JPanel panel = new JPanel(new FlowLayout());
    checkSC = new JCheckBox("Student Council");
    checkVW = new JCheckBox("Volunteer Work");
    panel.add(checkSC);
    panel.add(checkVW);
    return panel;
}

// Changing gridLayout()
public static JPanel gridLayout() {
    JPanel panel = new JPanel(new GridLayout(0, 2));
    panel.setSize(500, 500);
    panel.setPreferredSize(new Dimension(400, 400));
    Label labelArr[] = new Label[] { new Label("Name: "), new Label("Address: "), new Label("Province: "),
            new Label("City: "), new Label("Postal Code: "), new Label("Phone Number: "), new Label("Email: ") };

    nameField = new JTextField();
    addrField = new JTextField();
    provField = new JTextField();
    cityField = new JTextField();
    postField = new JTextField();
    phoneField = new JTextField();
    emailField = new JTextField();

    JTextField txtArr[] = new JTextField[] { nameField, addrField, provField, cityField, postField, phoneField,
            emailField };
    for (int i = 0; i < txtArr.length; i++) {
        panel.add(labelArr[i]);
        panel.add(txtArr[i]);
    }
    return panel;
}

// This is what your submit action would look like in createAndShowGUI().
submitBtn.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent arg0) {
        String name = nameField.getText();
        String addr = addrField.getText();
        String prov = provField.getText();
        String post = postField.getText();
        String phone = phoneField.getText();
        String email = emailField.getText();

        boolean isCS = radioCS.isSelected(); // If false then Business.
        boolean isCouncil = checkSC.isSelected();
        boolean isVolunteer = checkVW.isSelected();

        List<String> courses = new ArrayList<String>();
        for(int i=0; i<courseList.getModel().getSize(); i++) {
            courses.add(courseList.getModel().getElementAt(i));
        }

        txtArea.setText(name + " (" + phone + ") " + email + ". " + addr + ", " + prov + ", " + post+"\r\n");
        txtArea.append((isCS ? "Computer Science" : "Business")+". "+(isCouncil ? "Student Council, " : "")+(isVolunteer ? "Volunteer Work" : "")+". "+courses);
    }
});