从另一个类向Jlist提交数据

Question

I have a program where a window pops up. On that window is a JList and a button that says "add student" when you click that button another panel pops up that has JTextFields , and another button that says "add student." Whats supposed to happen is the user enters information into the text fields then clicks "add student" then that info is shown in the JList on the 1st panel.

Heres my code.

//This sends you to the other JPanel
private void btnAddStudentActionPerformed(java.awt.event.ActionEvent evt) {                                              

    AddStudent st = new AddStudent();
    st.setVisible(true);
} 


//This is supposed to send the information to the JList

    DefaultListModel model = new DefaultListModel();
private void btnAddStudentActionPerformed(java.awt.event.ActionEvent evt) {                                              


    setStudentVariables( txtFirstName.getText(), txtLastName.getText(), 12356, 3.55 );

    model.addElement( getMyStudent() );
    studentBox.setModel(model);   //Student box is the variable name for the JList
    setVisible(false);

}                                             

public static Student getMyStudent( /*String firstName, String lastName, int id, double gpa*/ ){

    Student s = new Student();
    s.setStudentFirstName( addFirstName );
    s.setStudentLastName( addLastName );
    s.setStudentID( addId );
    s.setStudentGPA( addGpa );

    System.out.println(addFirstName);

    return s;
}

public static void setStudentVariables( String firstName, String lastName, int id, double gpa ){
    addFirstName = firstName;
    addLastName = lastName;
    addId = id;
    addGpa = gpa;
}

//This is my student class

package school;

public class Student {

String studentFirstName, studentLastName;
int studentID;
double studentGPA;

Student(){}

public Student(String studentFirstName, String studentLastName, int studentID, double studentGPA) {
    this.studentFirstName = studentFirstName;
    this.studentLastName = studentLastName;
    this.studentID = studentID;
    this.studentGPA = studentGPA;
}

public void setStudentFirstName(String studentFirstName) {
    this.studentFirstName = studentFirstName;
}

public String getStudentFirstName() {
    return studentFirstName;
}

public void setStudentLastName(String studentLastName) {
    this.studentLastName = studentLastName;
}

public String getStudentLastName() {
    return studentLastName;
}

public void setStudentID(int studentID) {
    this.studentID = studentID;
}

public int getStudentID() {
    return studentID;
}

public void setStudentGPA(double studentGPA) {
    this.studentGPA = studentGPA;
}

public double getStudentGPA() {
    return studentGPA;
}  

public String toString() {
    return ("First Name:" + this.getStudentFirstName() +
                " Last Name " + this.getStudentLastName() +
                " ID: " + this.getStudentID() +
                " GPA: " + this.getStudentGPA());
}
}

Answer 1

I'm unclear exactly what you're asking for (or if there was even a question in your question), but it seems you're after something to this effect? (this is employing your Student class as shown)

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.JTextField;

public class Main {

    public static void main(String[] args) {
            final JFrame frame = new JFrame("JList!");
            frame.setDefaultCloseOperation(3);
            JPanel pane = new JPanel(new BorderLayout());
            final JList<Student> studentList = new JList<>();
            final DefaultListModel<Student> studentModel = new DefaultListModel<>();
            studentList.setModel(studentModel);
            pane.add(new JScrollPane(studentList), "Center");
            pane.add(new JButton(new AbstractAction("Add student") {

                @Override
                public void actionPerformed(ActionEvent arg0) {
                    JPanel pane = new JPanel(new GridLayout(0,2));
                    pane.add(new JLabel("First name:", JLabel.RIGHT));
                    JTextField fname = new JTextField();
                    pane.add(fname);
                    pane.add(new JLabel("Last name:", JLabel.RIGHT));
                    JTextField lname = new JTextField();
                    pane.add(lname);
                    pane.add(new JLabel("ID:", JLabel.RIGHT));
                    JTextField sid = new JTextField();
                    pane.add(sid);
                    pane.add(new JLabel("GPA:", JLabel.RIGHT));
                    JTextField gpa = new JTextField();
                    pane.add(gpa);
                    int result = JOptionPane.showOptionDialog(null, pane, "Add Student", JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE, null, null, null);
                    if(result == JOptionPane.OK_OPTION){
                        studentModel.addElement(new Student(fname.getText(), lname.getText(), Integer.parseInt(sid.getText()), Double.parseDouble(gpa.getText())));
                        studentList.updateUI();
                    }
                }
            }), "South");
            frame.setContentPane(pane);
            frame.setSize(400, 300);
            frame.setVisible(true);
    }

}

It ain't formatted the prettiest (ie at all), but hey, it adds a Student to the list, and is from another class (an anonymous inner class, but still another class technically).