java - 如何在 java.swing JTextField 中存储字符串或整数？

Question

您好，我正在开发这个项目来存储学生姓名并记录他们的成绩。我已经映射了整个程序，现在所需要做的就是记录用户输入中的整数和字符串，并从不同的类中调用它。我遇到了这个问题。我使用数组吗？我如何从另一个类(class)打电话？谢谢。

    package gradebook;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.util.Scanner;
import java.awt.event.ActionEvent;
import javax.swing.JTextArea;

public class Student extends JFrame {
    private JFrame studentFrame;
    private JPanel contentPane;
    private JTextField studentNameTextField;
    protected Component frame;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Student frame = new Student();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public Student() {

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        JLabel gradebookLabel = new JLabel("Gradebook");
        gradebookLabel.setBounds(189, 6, 68, 16);
        contentPane.add(gradebookLabel);

        JLabel lblPleaseEnterThe = new JLabel("Please enter the student name");
        lblPleaseEnterThe.setBounds(130, 105, 194, 16);
        contentPane.add(lblPleaseEnterThe);

        studentNameTextField = new JTextField("Enter here");
        String stdname = studentNameTextField.getText();
        studentNameTextField.setBounds(130, 133, 194, 26);
        contentPane.add(studentNameTextField);
        studentNameTextField.setColumns(10);

        JButton continueButton = new JButton("Continue");
        continueButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent a) {
                if(continueButton.isEnabled()){
                Student.this.dispose();
                    Student studentScreen = new Student();
                    studentScreen.dispose();

                    AddGrades addGradesScreen = new AddGrades();
                    addGradesScreen.setVisible(true);


                }
            }
        });
        continueButton.setBounds(327, 243, 117, 29);
        contentPane.add(continueButton);

        JButton cancelButton = new JButton("Cancel");
        cancelButton.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent a) {


                if(cancelButton.isEnabled()){




                    MainScreen mainScreenScreen = new MainScreen();
                    mainScreenScreen.setVisible(true);
                    contentPane.setVisible(false);
                    contentPane.disable();


                }
            }
        });


        cancelButton.setBounds(207, 243, 117, 29);
        contentPane.add(cancelButton);
    }

    private void initizalize() {
        // TODO Auto-generated method stub

    }
}

有类似的事情吗？

studentNameTextField = new JTextField("Enter here");
        String stdname = studentNameTextField.getText();

我知道这会存储它，但是我如何在不同的类中调用它，以便使它出现在不同的框架上？

更新:好的，我已经完成了

Student frame = new Student();
        String stdname = frame.studentNameTextField.getText();
        JLabel addgradesLabel = new JLabel("Add grades for" + frame.studentNameTextField);
        addgradesLabel.setBounds(139, 34, 167, 29);
        contentPane.add(addgradesLabel);

但它仍然不起作用。我相信我没有正确实现这一点。我试图用用户输入的名称来为标签命名。所以它会“为”添加成绩+ stdname 但它没有正确调用它。我该如何解决这个问题？

这是我的 AddStudentName 类的代码

studentNameTextField = new JTextField();
        studentNameTextField.setBounds(130, 133, 194, 26);
        contentPane.add(studentNameTextField);
        studentNameTextField.setColumns(10);

        JButton continueButton = new JButton("Continue");
        continueButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent a) {
                if(continueButton.isEnabled()){
                Student.this.dispose();
                    Student studentScreen = new Student();
                    studentScreen.dispose();


                    AddGrades addGradesScreen = new AddGrades();
                    addGradesScreen.setVisible(true);




                }
            }
        });

我应该在此处添加什么来保存用户在 JTextField 中输入的内容？感谢您的帮助

以下是这些类的完整代码:

package gradebook;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.util.Scanner;
import java.awt.event.ActionEvent;
import javax.swing.JTextArea;

public class Student extends JFrame {
    private JFrame studentFrame;
    private JPanel contentPane;
    public JTextField studentNameTextField;
    protected Component frame;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Student frame = new Student();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public Student() {

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        JLabel gradebookLabel = new JLabel("Gradebook");
        gradebookLabel.setBounds(189, 6, 68, 16);
        contentPane.add(gradebookLabel);

        JLabel lblPleaseEnterThe = new JLabel("Please enter the student name");
        lblPleaseEnterThe.setBounds(130, 105, 194, 16);
        contentPane.add(lblPleaseEnterThe);


        JTextField studentNameTextField = new JTextField();

        studentNameTextField.setBounds(130, 133, 194, 26);
        contentPane.add(studentNameTextField);
        studentNameTextField.setColumns(10);

        JButton continueButton = new JButton("Continue");
        continueButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent a) {
                if(continueButton.isEnabled()){

                    Student studentScreen = new Student();
                    studentScreen.dispose();

                    AddGrades addGradesScreen = new AddGrades();
                    addGradesScreen.setVisible(true);



                }
            }
        });


        continueButton.setBounds(327, 243, 117, 29);
        contentPane.add(continueButton);

        JButton cancelButton = new JButton("Cancel");
        cancelButton.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent a) {


                if(cancelButton.isEnabled()){




                    MainScreen mainScreenScreen = new MainScreen();
                    mainScreenScreen.setVisible(true);
                    contentPane.setVisible(false);
                    contentPane.disable();


                }
            }
        });


        cancelButton.setBounds(207, 243, 117, 29);
        contentPane.add(cancelButton);
    }

    private void initizalize() {
        // TODO Auto-generated method stub

    }
}

和:

package gradebook;

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class AddGrades extends JFrame {

    private JPanel contentPane;
    private JTextField Assignment1;
    private JTextField Assignment2;
    private JTextField Assignment3;
    private JTextField Assignment4;
    private JLabel testsLabel;
    private JTextField Test1;
    private JTextField Test2;
    public JTextField Test3;
    public JTextField Test4;

    /**
     * Launch the application.
     */
    public JFrame frame;
    public JButton continueButton;
    public JButton exitButton;
    public static void main(String[] args) {
        AddGrades frame = new AddGrades();
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    AddGrades frame = new AddGrades();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public AddGrades() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        JLabel gradebookLabel = new JLabel("Gradebook");
        gradebookLabel.setBounds(189, 6, 68, 16);
        contentPane.add(gradebookLabel);


        JLabel addgradesLabel = new JLabel("Add grades for" + stdname);
        addgradesLabel.setBounds(139, 34, 167, 29);
        contentPane.add(addgradesLabel);

        JLabel assignmentsLabel = new JLabel("Assignments:");
        assignmentsLabel.setBounds(19, 75, 86, 16);
        contentPane.add(assignmentsLabel);

        Assignment1 = new JTextField();
        Assignment1.setBounds(54, 91, 130, 26);
        contentPane.add(Assignment1);
        Assignment1.setColumns(10);

        Assignment2 = new JTextField();
        Assignment2.setBounds(54, 129, 130, 26);
        contentPane.add(Assignment2);
        Assignment2.setColumns(10);

        Assignment3 = new JTextField();
        Assignment3.setBounds(54, 167, 130, 26);
        contentPane.add(Assignment3);
        Assignment3.setColumns(10);

        Assignment4 = new JTextField();
        Assignment4.setBounds(54, 205, 130, 26);
        contentPane.add(Assignment4);
        Assignment4.setColumns(10);

        testsLabel = new JLabel("Tests:");
        testsLabel.setBounds(243, 75, 38, 16);
        contentPane.add(testsLabel);

        Test1 = new JTextField();
        Test1.setBounds(262, 91, 130, 26);
        contentPane.add(Test1);
        Test1.setColumns(10);

        Test2 = new JTextField();
        Test2.setBounds(262, 129, 130, 26);
        contentPane.add(Test2);
        Test2.setColumns(10);

        Test3 = new JTextField();
        Test3.setBounds(262, 167, 130, 26);
        contentPane.add(Test3);
        Test3.setColumns(10);

        Test4 = new JTextField();
        Test4.setBounds(262, 205, 130, 26);
        contentPane.add(Test4);
        Test4.setColumns(10);

        continueButton = new JButton("Continue");
        continueButton.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent a){
                if (continueButton.isEnabled()){

                    MainScreen mainScreenScreen = new MainScreen();
                    mainScreenScreen.setVisible(true);

                }


            }
        });
        continueButton.setBounds(327, 243, 117, 29);
        contentPane.add(continueButton);

        exitButton = new JButton("Exit");

        exitButton.setBounds(208, 243, 117, 29);
        contentPane.add(exitButton);
    }
}

我正在尝试从 JTextField 获取输入

JTextField studentNameTextField = new JTextField();

并将其设置在标签上

JLabel addgradesLabel = new JLabel("Add grades for" + stdname);

其中 stdname 是来自 JTextField 的用户输入。

现在我收到错误

public static void main(String[] args) {
        AddGrades frame = new AddGrades();
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    AddGrades frame = new AddGrades();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

AddGrades 框架 = new AddGrades();给我错误添加参数以匹配 AddGrades(String)

构造函数 AddGrades() 未定义

Answer 1

编辑:执行此操作的最佳方法是将参数传递给新创建的 AddGrades 类。见下文:

public AddGrades(String stdname) {
    JLabel addgradesLabel = new JLabel("Add grades for " + stdname);
}

您需要修改代码以将字符串传递到您创建的 AddGrades 类:

JButton continueButton = new JButton("Continue");
continueButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent a) {
        if(continueButton.isEnabled()){

            Student studentScreen = new Student();
            studentScreen.dispose();

            AddGrades addGradesScreen = new AddGrades(studentNameTextField.getText());
            addGradesScreen.setVisible(true);
        }
    }
});

这对我有用 - 我下载了你的代码并测试了它。