尝试从 JTextField 设置字符串

Question

这就是我正在做的事情 查看 StudentIDPrint 的 JLabel 将它们打印出来，还有带有文本字段的字符串的 StudentIDSS 是 StudentIDSS 应该从中获得其价值的地方我真的很喜欢任何提示和帮助，非常感谢我认为这可能是放置代码的地方，但我真的迷失在这里，任何帮助都会很可爱，非常感谢大家

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
//Allows it too use JFrame
public class LiftingApp extends JFrame {
    //Calls them from import (like calling a Scanner)
    private JLabel EnterSID;
    private JButton button;
    private JTextField textfield;
    private ImageIcon image;
    private JLabel WaukeeAPEX;
    private ImageIcon ThankIMG;
    private JLabel Thank;
    private JButton AdminButton;
    private JTextField AdminText;
    private JButton AdminButton2;
    private JLabel AdminThank;
    private JButton goback;
    private ImageIcon Login;
    private ImageIcon AdminLogin;
    private ImageIcon RTMS;
    private JLabel StudentIDPrint;
    public String StudentIDSS;
    public LiftingApp() 
    {
        getContentPane().setBackground(Color.GRAY);
        setIconImage(Toolkit.getDefaultToolkit().getImage(LiftingApp.class.getResource("ICON.jpg")));
        getContentPane().setLayout(new FlowLayout());
                goback = new JButton("Return To Main Screen");
                getContentPane().add(goback);
                goback.setVisible(false);
                event4 rb = new event4();
                goback.addActionListener(rb);
                AdminThank = new JLabel("Thank You For Loging in");
                AdminThank.setForeground(Color.WHITE);
                getContentPane().add(AdminThank);
                AdminThank.setVisible(false);
                AdminButton2 = new JButton("Admin Login");
                getContentPane().add(AdminButton2);
                AdminButton2.setVisible(false);
                event3 al2 = new event3();
                AdminButton2.addActionListener(al2);
                AdminButton = new JButton("Admin Login");
                getContentPane().add(AdminButton);
                AdminText = new JTextField(10);
                getContentPane().add(AdminText);
                AdminText.setVisible(false);
                event2 al = new event2();
                AdminButton.addActionListener(al);
                //Adds a Button
                button = new JButton("Login");
                getContentPane().add(button);               
                //Adds Text
                EnterSID = new JLabel("Enter StudentID");
                EnterSID.setForeground(Color.WHITE);
                getContentPane().add(EnterSID);
                event e = new event();
                button.addActionListener(e);
                //Adds Field (The box you type stuff in) 
                textfield = new JTextField(10);
                getContentPane().add(textfield);
                textfield.getText();
                //Adds Image
                image = new ImageIcon(getClass() .getResource("testt.png"));
                //Sets Image to the WaukeeAPEX JLabel
                WaukeeAPEX = new JLabel(image);
                getContentPane().add(WaukeeAPEX);
                ThankIMG = new ImageIcon(getClass() .getResource("testt2.png"));
                Thank = new JLabel(ThankIMG);
                getContentPane().add(Thank);
                Thank.setVisible(false);                
                StudentIDPrint = new JLabel();
                getContentPane().add(StudentIDPrint);
                StudentIDPrint.setVisible(false);
                StudentIDPrint.setText("Student IDS Are:" + StudentIDSS);       
    }               
    public static void main(String[] args)
    {       
        //This is just talking about the window
        LiftingApp gui = new LiftingApp();
        //When you click the X it closes...
        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //Size of intial box (pack puts every thing you have to the smallest size to keep everything)
        gui.setSize(1000, 1000);
        //This makes it so you can see the Window
        gui.setVisible(true);
        //This Sets The Title
        gui.setTitle("Elmin Strength");

        //Dont Worry About any of this just learning Arrays
        //Array Initializer
    }
    //ActionListener Just waits for the action to happen then dose what is told
    public class event implements ActionListener {
        //Telling what the Action is
        public void actionPerformed(ActionEvent e) {
            StudentIDSS = textfield.getText();
            //This will show after the button is pressed
            EnterSID.setVisible(false);
            textfield.setVisible(true);
            Thank.setVisible(true);
            AdminText.setVisible(false);
            AdminButton.setVisible(false);
            button.setVisible(false);
            WaukeeAPEX.setVisible(false);
            textfield.setVisible(false);
            goback.setVisible(true);
        }
    }
    public class event2 implements ActionListener{
        public void actionPerformed(ActionEvent al){
            textfield.setVisible(false);

            EnterSID.setVisible(false);
            button.setVisible(false);
            AdminText.setVisible(true);
            AdminButton.setVisible(false);
            AdminButton2.setVisible(true);          
            goback.setVisible(true);
        }

    }
    public class event3 implements ActionListener{
        public void actionPerformed(ActionEvent al2){
            String p = AdminText.getText();
            AdminButton2.setVisible(false);
            textfield.setVisible(false);
            AdminText.setVisible(true);
            AdminText.getSelectedText();
            WaukeeAPEX.setVisible(false);
            if(p.compareTo("Password") == 0) {
            Thank.setVisible(true);
            goback.setVisible(true);
            AdminThank.setVisible(true);
            StudentIDPrint.setVisible(true);
            }else{
                goback.setVisible(true);
                AdminText.setVisible(false);
            }
        }
    }
    public class event4 implements ActionListener{
        public void actionPerformed(ActionEvent rb) {
            goback.setVisible(false);
            button.setVisible(true);
            EnterSID.setVisible(true);
            textfield.setVisible(true);
            AdminButton.setVisible(true);
            WaukeeAPEX.setVisible(true);
            Thank.setVisible(false);
            AdminButton2.setVisible(false);
            AdminThank.setVisible(false);
            AdminText.setVisible(false);
        }
    }
}

Answer 1

我不知道

你在玩什么LiftingApp。为了方便起见，我重新排列了您的一些代码。

public LiftingApp() {   
    // skip... 
    getContentPane().setLayout(new FlowLayout());
    getContentPane().add(goback);
    getContentPane().add(AdminThank);
    getContentPane().add(AdminButton2);
    getContentPane().add(AdminButton);
    getContentPane().add(AdminText);
    getContentPane().add(button);
    getContentPane().add(EnterSID);
    getContentPane().add(textfield);
    getContentPane().add(WaukeeAPEX);
    getContentPane().add(Thank);
    getContentPane().add(StudentIDPrint);
    event4 rb = new event4();
    event3 al2 = new event3();
    event2 al = new event2();
    event e = new event();
    goback.addActionListener(rb);
    AdminButton2.addActionListener(al2);
    AdminButton.addActionListener(al);
    button.addActionListener(e);
    goback.setVisible(false);
    AdminThank.setVisible(false);
    AdminButton2.setVisible(false);
    AdminText.setVisible(false);
    Thank.setVisible(false);
    StudentIDPrint.setVisible(false);
}

现在，您有一个 FlowLayout 作为类的布局，其中包含 4 个按钮和 4 个操作侦听器。

对于这些操作，您只有一个侦听器就足够了。

我只是将每个侦听器的代码作为 MainEvent 类放到一个侦听器上。如您所知，有几种方法可以使用操作侦听器。这可能是一种方法。

class MainButtonEvt implements ActionListener
{
    @Override
    public void actionPerformed(ActionEvent evt) {
        System.out.println("====> ");
        if(evt.getSource() == (JButton) button)
        {
            System.out.println("====> login");
            StudentIDSS = textfield.getText();
            StudentIDPrint.setText("Student IDS Are:" + StudentIDSS);
            if(!StudentIDPrint.isVisible()) StudentIDPrint.setVisible(true);
            // This will show after the button is pressed
            if(EnterSID.isVisible()) EnterSID.setVisible(false);
            if(!textfield.isVisible()) textfield.setVisible(true);
            if(!Thank.isVisible()) Thank.setVisible(true);
            if(AdminText.isVisible()) AdminText.setVisible(false);
            if(AdminButton.isVisible()) AdminButton.setVisible(false);
            if(button.isVisible()) button.setVisible(false);
            if(WaukeeAPEX.isVisible()) WaukeeAPEX.setVisible(false);
            if(AdminThank.isVisible()) AdminThank.setVisible(false);
            if(!goback.isVisible()) goback.setVisible(true);
        }
        if(evt.getSource() == (JButton) goback)
        {
            System.out.println("====> goback");
            String p = textfield.getText();
            if(p != null && !p.equals(""))  textfield.setText("");
            if(goback.isVisible()) goback.setVisible(false);
            if(!button.isVisible()) button.setVisible(true);
            if(!EnterSID.isVisible()) EnterSID.setVisible(true);
            if(textfield.isVisible()) textfield.setVisible(false);
            if(!AdminButton.isVisible()) AdminButton.setVisible(true);
            if(!WaukeeAPEX.isVisible()) WaukeeAPEX.setVisible(true);
            if(Thank.isVisible()) Thank.setVisible(false);
            if(AdminButton2.isVisible()) AdminButton2.setVisible(false);
            if(AdminThank.isVisible()) AdminThank.setVisible(false);
            if(!AdminText.isVisible()) AdminText.setVisible(true);
        }
        if(evt.getSource() == (JButton) AdminButton)
        {
            System.out.println("====> AdminButton");

            if(AdminButton2.isVisible()) AdminButton2.setVisible(false);
            if(textfield.isVisible()) textfield.setVisible(false);
            if(!AdminText.isVisible()) AdminText.setVisible(true);
            String p = AdminText.getText();
            //p = AdminText.getSelectedText();
            if(WaukeeAPEX.isVisible()) WaukeeAPEX.setVisible(false);
            if (p.compareTo("Password") == 0) {
                if(!Thank.isVisible()) Thank.setVisible(true);
                if(!goback.isVisible()) goback.setVisible(true);
                if(!AdminThank.isVisible()) AdminThank.setVisible(true);
                if(!StudentIDPrint.isVisible()) 
                    StudentIDPrint.setVisible(true);
            } else {
                if(!goback.isVisible()) goback.setVisible(true);
                if(AdminText.isVisible()) AdminText.setVisible(false);
            }
        }
    }
}

然后，您可以按如下方式调用主事件类;

MainButtonEvt mainEvt = new MainButtonEvt();
goback.addActionListener(mainEvt);
AdminButton2.addActionListener(mainEvt);
AdminButton.addActionListener(mainEvt);
button.addActionListener(mainEvt);

我希望你能找到如何处理它。完整源代码：

package just.test.swing;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.File;
import java.net.MalformedURLException;
//Allows it too use JFrame
public class LiftingApp extends JFrame {
    // Calls them from import (like calling a Scanner)
    private JLabel EnterSID;
    private JButton button;
    private JTextField textfield;
    private ImageIcon image;
    private JLabel WaukeeAPEX;
    private ImageIcon ThankIMG;
    private JLabel Thank;
    private JButton AdminButton;
    private JTextField AdminText;
    private JButton AdminButton2;
    private JLabel AdminThank;
    private JButton goback;
    private ImageIcon Login;
    private ImageIcon AdminLogin;
    private ImageIcon RTMS;
    private JLabel StudentIDPrint;
    public String StudentIDSS;
    public LiftingApp() {
        getContentPane().setBackground(Color.GRAY);
        File icon = new File("resource/images/hourglass.png");
        File icon2 = new File("resource/images/plus.png");
        File icon3 = new File("resource/images/minus.png");
        // setIconImage(Toolkit.getDefaultToolkit().getImage(LiftingApp.class.getResource("ICON.jpg")));
        try {
            setIconImage(Toolkit.getDefaultToolkit().getImage(icon.toURI().toURL()));
        } catch (MalformedURLException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        goback = new JButton("Return To Main Screen");
        AdminThank = new JLabel("Thank You For Loging in");
        AdminThank.setForeground(Color.WHITE);
        AdminButton2 = new JButton("Admin Login2");
        AdminButton = new JButton("Admin Login");
        AdminText = new JTextField(10);
        // Adds a Button
        button = new JButton("Login");
        // Adds Text
        EnterSID = new JLabel("Enter StudentID");
        EnterSID.setForeground(Color.WHITE);
        // Adds Field (The box you type stuff in)
        textfield = new JTextField(10);
        //textfield.getText();
        // Adds Image
        // image = new ImageIcon(getClass().getResource("testt.png"));
        try {
            image = new ImageIcon(icon2.toURI().toURL());
        } catch (MalformedURLException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        // Sets Image to the WaukeeAPEX JLabel
        WaukeeAPEX = new JLabel(image);
        // ThankIMG = new ImageIcon(getClass() .getResource("testt2.png"));
        try {
            ThankIMG = new ImageIcon(icon3.toURI().toURL());
        } catch (MalformedURLException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        Thank = new JLabel(ThankIMG);
        StudentIDPrint = new JLabel();
        StudentIDSS = "";
        StudentIDPrint.setText("Student IDS Are:" + StudentIDSS);
        getContentPane().setLayout(new FlowLayout());

        getContentPane().add(goback);
        getContentPane().add(AdminThank);
        getContentPane().add(AdminButton2);
        getContentPane().add(AdminButton);
        getContentPane().add(AdminText);
        getContentPane().add(button);
        getContentPane().add(EnterSID);
        getContentPane().add(textfield);
        getContentPane().add(WaukeeAPEX);
        getContentPane().add(Thank);
        getContentPane().add(StudentIDPrint);

        MainButtonEvt mainEvt = new MainButtonEvt();
        goback.addActionListener(mainEvt);
        AdminButton2.addActionListener(mainEvt);
        AdminButton.addActionListener(mainEvt);
        button.addActionListener(mainEvt);
        //event4 rb = new event4();
        //event3 al2 = new event3();
        //event2 al = new event2();
        //event e = new event();
        //goback.addActionListener(rb);
        //AdminButton2.addActionListener(al2);
        //AdminButton.addActionListener(al);
        //button.addActionListener(e);
        goback.setVisible(false);
        AdminThank.setVisible(false);
        AdminButton2.setVisible(false);
        AdminText.setVisible(false);
        Thank.setVisible(false);
        StudentIDPrint.setVisible(false);
    }
    public static void main(String[] args) {
        // This is just talking about the window
        LiftingApp gui = new LiftingApp();
        // When you click the X it closes...
        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        // Size of intial box (pack puts every thing you have to the smallest
        // size to keep everything)
        gui.setSize(1200, 900);
        // This makes it so you can see the Window
        gui.setVisible(true);
        // This Sets The Title
        gui.setTitle("Elmin Strength");
        // Dont Worry About any of this just learning Arrays
        // Array Initializer
    }
    class MainButtonEvt implements ActionListener
    {
        @Override
        public void actionPerformed(ActionEvent evt) {
            System.out.println("====> ");
            if(evt.getSource() == (JButton) button)
            {
                System.out.println("====> login");
                StudentIDSS = textfield.getText();
                StudentIDPrint.setText("Student IDS Are:" + StudentIDSS);
                if(!StudentIDPrint.isVisible()) StudentIDPrint.setVisible(true);
                // This will show after the button is pressed
                if(EnterSID.isVisible()) EnterSID.setVisible(false);
                if(!textfield.isVisible()) textfield.setVisible(true);
                if(!Thank.isVisible()) Thank.setVisible(true);
                if(AdminText.isVisible()) AdminText.setVisible(false);
                if(AdminButton.isVisible()) AdminButton.setVisible(false);
                if(button.isVisible()) button.setVisible(false);
                if(WaukeeAPEX.isVisible()) WaukeeAPEX.setVisible(false);
                if(AdminThank.isVisible()) AdminThank.setVisible(false);
                if(!goback.isVisible()) goback.setVisible(true);
            }
            if(evt.getSource() == (JButton) goback)
            {
                System.out.println("====> goback");
                String p = textfield.getText();
                if(p != null && !p.equals(""))  textfield.setText("");
                if(goback.isVisible()) goback.setVisible(false);
                if(!button.isVisible()) button.setVisible(true);
                if(!EnterSID.isVisible()) EnterSID.setVisible(true);
                if(textfield.isVisible()) textfield.setVisible(false);
                if(!AdminButton.isVisible()) AdminButton.setVisible(true);
                if(!WaukeeAPEX.isVisible()) WaukeeAPEX.setVisible(true);
                if(Thank.isVisible()) Thank.setVisible(false);
                if(AdminButton2.isVisible()) AdminButton2.setVisible(false);
                if(AdminThank.isVisible()) AdminThank.setVisible(false);
                if(!AdminText.isVisible()) AdminText.setVisible(true);
            }
            if(evt.getSource() == (JButton) AdminButton)
            {
                System.out.println("====> AdminButton");

                if(AdminButton2.isVisible()) AdminButton2.setVisible(false);
                if(textfield.isVisible()) textfield.setVisible(false);
                if(!AdminText.isVisible()) AdminText.setVisible(true);
                String p = AdminText.getText();
                //p = AdminText.getSelectedText();
                if(WaukeeAPEX.isVisible()) WaukeeAPEX.setVisible(false);
                if (p.compareTo("Password") == 0) {
                    if(!Thank.isVisible()) Thank.setVisible(true);
                    if(!goback.isVisible()) goback.setVisible(true);
                    if(!AdminThank.isVisible()) AdminThank.setVisible(true);
                    if(!StudentIDPrint.isVisible()) StudentIDPrint.setVisible(true);
                } else {
                    if(!goback.isVisible()) goback.setVisible(true);
                    if(AdminText.isVisible()) AdminText.setVisible(false);
                }
            }
        }
    }
    // ActionListener Just waits for the action to happen then dose what is told
    public class event implements ActionListener {
        // Telling what the Action is
        public void actionPerformed(ActionEvent e) {
            StudentIDSS = textfield.getText();
            // This will show after the button is pressed
            EnterSID.setVisible(false);
            textfield.setVisible(true);
            Thank.setVisible(true);
            AdminText.setVisible(false);
            AdminButton.setVisible(false);
            button.setVisible(false);
            WaukeeAPEX.setVisible(false);
            textfield.setVisible(false);
            goback.setVisible(true);
        }
    }
    public class event2 implements ActionListener {
        public void actionPerformed(ActionEvent al) {
            textfield.setVisible(false);
            EnterSID.setVisible(false);
            button.setVisible(false);
            AdminText.setVisible(true);
            AdminButton.setVisible(false);
            AdminButton2.setVisible(true);
            goback.setVisible(true);
        }
    }
    public class event3 implements ActionListener {
        public void actionPerformed(ActionEvent al2) {
            String p = AdminText.getText();
            AdminButton2.setVisible(false);
            textfield.setVisible(false);
            AdminText.setVisible(true);
            AdminText.getSelectedText();
            WaukeeAPEX.setVisible(false);
            if (p.compareTo("Password") == 0) {
                Thank.setVisible(true);
                goback.setVisible(true);
                AdminThank.setVisible(true);
                StudentIDPrint.setVisible(true);
            } else {
                goback.setVisible(true);
                AdminText.setVisible(false);
            }
        }
    }
    public class event4 implements ActionListener {
        public void actionPerformed(ActionEvent rb) {
            goback.setVisible(false);
            button.setVisible(true);
            EnterSID.setVisible(true);
            textfield.setVisible(true);
            AdminButton.setVisible(true);
            WaukeeAPEX.setVisible(true);
            Thank.setVisible(false);
            AdminButton2.setVisible(false);
            AdminThank.setVisible(false);
            AdminText.setVisible(false);
        }
    }
}

Answer 2

首先 抱歉发布我的整个代码，其次我所做的是制作一个从 JTextField 获取的 JLabel，然后我制作了一个从 JLabel 获取的字符串

StudentIDSSS = new JLabel(": " + textfield.getText() + ":");
			getContentPane().add(StudentIDSSS);
			StudentIDSSS.setVisible(true);
			
			String List = StudentIDSSS.getText();
			
			System.out.print(List);
			
			StudentIDList = new JLabel(List);
			getContentPane().add(StudentIDList);
			StudentIDList.setVisible(false);