java - 将 JMenu 添加到我的 JPanel

Question

我是编码新手，想知道为什么我的 JMenuBar 不会显示？ 这是代码，谢谢! :)

package vp.hendrasetiawan.pkg20413017.week4no2;


public class VPHendraSetiawan20413017Week4No2 {


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

}

MainFrame.java

package vp.hendrasetiawan.pkg20413017.week4no2;

import javax.swing.JFrame;

public class MainFrame extends JFrame {

public MainFrame() {
    this.setContentPane(new PeriodFormPanel());
    this.pack();
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setVisible(true);
}
}

期间表格面板

package vp.hendrasetiawan.pkg20413017.week4no2;

import com.jgoodies.forms.layout.CellConstraints;
import com.jgoodies.forms.layout.FormLayout;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ButtonGroup;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class PeriodFormPanel extends JPanel {

private JLabel titleLabel, fieldLabel;
private JTextArea expertise;
private JTextField idField,
                   nameField,
                   dob1Field, dob2Field, dob3Field,
                   address1Field, address2Field,
                   phoneField,
                   emailField, image;
private ButtonGroup group = new ButtonGroup();
private JRadioButton genderFbutton, genderMbutton;
private JButton backButton,
                saveButton,
                cancelButton;

private JMenu login, student, kelas, teacher, presence;

private JMenuItem logout, change,
                  newStudent, listStudent, joinClass, payment, 
                                                      newpayment, history,
                  course,
                  newCourse, listCourse,

                  activeClass,
                  newActiveClass, listActiveClass,

                  newTeacher, listTeacher,

                  spresence, tpresence;

private JButton btnImage;

public PeriodFormPanel() {
    this.setPreferredSize(new Dimension(450,750));
    buildLayout();

}

public void buildLayout() { 
    titleLabel = new JLabel("Teacher Form");
    titleLabel.setFont(new Font("Times New Roman",Font.BOLD, 20));
    idField = new JTextField();
    nameField = new JTextField();

    genderFbutton = new JRadioButton("Female");
    genderMbutton = new JRadioButton("Male", true);
    group.add(genderFbutton);
    group.add(genderMbutton);

    dob1Field = new JTextField();
    dob2Field = new JTextField();
    dob3Field = new JTextField();

    address1Field = new JTextField();
    address2Field = new JTextField();

    phoneField = new JTextField();
    emailField = new JTextField();

    expertise = new JTextArea(
              "Piano \n"
            + "Guitar \n"
            + "Vocal \n"
            + "Drum \n"
            + "Violin \n \n \n");





    backButton = new JButton("<< Back");
    saveButton = new JButton("Save");
    cancelButton = new JButton("Cancel");

    //create a menu bar
    final JMenuBar menuBar = new JMenuBar();

    //create menus
    login = new JMenu("Login");
    student = new JMenu("Student"); 
    kelas = new JMenu("Class");
    teacher = new JMenu("Teacher");
    presence = new JMenu("Presence");

    //create menus
  JMenu fileMenu = new JMenu("File");
  JMenu editMenu = new JMenu("Edit"); 
  final JMenu aboutMenu = new JMenu("About");
  final JMenu linkMenu = new JMenu("Links");

  //create menu items

  //Login
  logout = new JMenuItem("Logout");
  change = new JMenuItem("Change Password");

  //Student
  newStudent = new JMenuItem("New Student");
  listStudent = new JMenuItem("List of Student");
  joinClass = new JMenuItem("Join Class");
  payment = new JMenuItem("Payment");
  //Payment SubMenu
  payment.add(new JMenuItem("New Payment"));
  payment.add(new JMenuItem("History"));

  //Class
  course = new JMenuItem("Course");
  //Course SubMenu
  course.add(new JMenuItem("New Course"));
  course.add(new JMenuItem("List of Course"));

  activeClass = new JMenuItem("Active Class");
  //ActiveClass SubMenu
  activeClass.add(new JMenuItem("New Active Class"));
  activeClass.add(new JMenuItem("List of Active Class"));

  //Teacher
  newTeacher = new JMenuItem("New Teacher");
  listTeacher = new JMenuItem("List of Teacher");

  //Presence
  spresence = new JMenuItem("Student's Presence");
  tpresence = new JMenuItem("Teacher's Presence");

  login.add(logout);
  login.add(change);

  student.add(newStudent);
  student.add(listStudent);
  student.add(joinClass);
  student.add(payment);

  kelas.add(course);
  kelas.add(activeClass);

  teacher.add(newTeacher);
  teacher.add(listTeacher);

  presence.add(spresence);
  presence.add(tpresence);

                       //1     2    3     4     5     6     7     8     9     10    11    12    13    14    15   16     17     18    19    20    21
    String colSizes = "20px, pref, 25px, pref, 20px, 30px, 20px, 30px, 20px, 20px, 20px, 70px, 20px";
    String rowSizes = "20px, pref, 20px, pref, 20px, pref, 20px, pref, 20px, pref, 20px, pref, 20px, pref, 20px, pref, 10px, 120px, 20px, pref, 20px, 200px";

    FormLayout layout = new FormLayout(colSizes, rowSizes);
    this.setLayout(layout);

    CellConstraints cc = new CellConstraints();
    //Student Form
    this.add(titleLabel, cc.xywh(2, 2, 3, 1));

    //ID
    fieldLabel = new JLabel("ID");
    this.add(fieldLabel, cc.xywh(2, 4, 1, 1));
    this.add(idField, cc.xywh(4, 4, 2, 1));
    idField.setEditable(false);

    //Name
    fieldLabel = new JLabel("Name");
    this.add(fieldLabel, cc.xywh(2, 6, 1, 1));
    this.add(nameField, cc.xywh(4, 6, 9, 1));

    //Gender
    fieldLabel = new JLabel("Gender");
    this.add(fieldLabel, cc.xywh(2, 8, 1, 1));

    this.add(genderFbutton, cc.xywh(4, 8, 1, 1));
    this.add(genderMbutton, cc.xywh(6, 8, 3, 1));

    //DOB
    fieldLabel = new JLabel("D.O.B");
    this.add(fieldLabel, cc.xywh(2, 10, 1, 1));

    this.add(dob1Field, cc.xywh(4, 10, 1, 1));
    this.add(dob2Field, cc.xywh(6, 10, 3, 1));
    this.add(dob3Field, cc.xywh(10, 10, 3, 1));

    //Address
    fieldLabel = new JLabel("Address");
    this.add(fieldLabel, cc.xywh(2, 12, 1, 1));

    this.add(address1Field, cc.xywh(4, 12, 7, 1));
    this.add(address2Field, cc.xywh(12, 12, 1, 1));

    //Phone
    fieldLabel = new JLabel("Phone");
    this.add(fieldLabel, cc.xywh(2, 14, 1, 1));
    this.add(phoneField, cc.xywh(4, 14, 3, 1));

    //Email
    fieldLabel = new JLabel("Email");
    this.add(fieldLabel, cc.xywh(2, 16, 1, 1));
    this.add(emailField, cc.xywh(4, 16, 3, 1));

    //Expertise
    fieldLabel = new JLabel("Expertise");

    this.add(fieldLabel, cc.xywh(2, 17, 1, 2));
    this.add(expertise, cc.xywh(4, 18, 3, 1));

    //Image
    BufferedImage image = null;
    try 
    {
        image = ImageIO.read(new File("Box.jpg"));
    }
    catch(IOException ex)
    {
        System.out.println("Gambar Tidak Ditemukan");
    }
    JLabel picLabel = new JLabel(new ImageIcon(image));

    this.add((picLabel), cc.xywh(8, 14, 5, 5));

    //Back
    backButton.setPreferredSize(new Dimension(50,25));
    backButton.setFont(new Font("Times New Roman",Font.BOLD, 10)); //Font - Bold - Size
    this.add(backButton, cc.xywh(2, 20, 2, 1));

    //Save
    saveButton.setPreferredSize(new Dimension(50,25));
    saveButton.setFont(new Font("Times New Roman",Font.BOLD, 10));
    this.add(saveButton, cc.xywh(8, 20, 3, 1));

    //Cancel
    cancelButton.setPreferredSize(new Dimension(50,25));
    cancelButton.setFont(new Font("Times New Roman",Font.BOLD, 10));
    this.add(cancelButton, cc.xywh(12, 20, 1, 1));

    //Button Image

    BufferedImage image1 = null;
    try 
    {
        image = ImageIO.read(new File("pixel.png"));
    }
    catch(IOException ex)
    {
        System.out.println("Gambar Tidak Ditemukan");
    }
   btnImage = new JButton(new ImageIcon(image));

    this.add((btnImage), cc.xywh(8, 22, 5, 1));

}
} 

Answer 1

1)向PeriodFormPanel添加一个字段

  private JMenuBar menuBar;

2)向PeriodFormPanel添加getter

 public JMenuBar getMenuBar() {
return menuBar;

}

3) 在PeriodFormPanel 中的buildLayout 函数末尾执行此代码

   menuBar.add(login);
   menuBar.add(student);
   menuBar.add(kelas);
   menuBar.add(teacher);
   menuBar.add(presence);
  this.menuBar = menuBar;

4)更改您的大型机构造函数

public MainFrame() {
    PeriodFormPanel periodFormPanel = new PeriodFormPanel();
    this.setJMenuBar(periodFormPanel.getMenuBar());
    this.setContentPane(periodFormPanel);
    this.pack();

    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   this.setVisible(true);

}