所以我有了这段代码，可以打开登录页面和一个简单的主页。 这也包括ActionListeners。

类Login扩展JFrame实现ActionListener{

   JPanel panel;
   JLabel user_label, password_label, message;
   JTextField userName_text;
   JPasswordField password_text;
   JButton submit, cancel;
   
   Login() {
       
      user_label = new JLabel();
      user_label.setText("Username :");
      userName_text = new JTextField();
      
      password_label = new JLabel();
      password_label.setText("Password :");
      password_text = new JPasswordField();
      
      submit = new JButton("SUBMIT");
      panel = new JPanel(new GridLayout(3, 1));
      panel.add(user_label);
      panel.add(userName_text);
      panel.add(password_label);
      panel.add(password_text);
      message = new JLabel();
      panel.add(message);
      panel.add(submit);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      
      submit.addActionListener(this);
      add(panel, BorderLayout.CENTER);
      setTitle("Please Login Here !");
      setSize(350,250);
      setVisible(true);
   }
   public static void main(String[] args) {
      new Login();
   }
   @Override
   public void actionPerformed(ActionEvent ae) {
      String userName = userName_text.getText();
      @SuppressWarnings("deprecation")
    String password = password_text.getText();
      boolean args;
    if (userName.trim().equals("LOL") && password.trim().equals("12345")) {
        {JFrame frame = new JFrame("Welcome Back, (Insert username here)!");
          frame.setVisible(true);
          frame.setSize(1000,1000);
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

          JLabel textLabel = new JLabel("Total Steps",SwingConstants.CENTER); 
          textLabel.setPreferredSize(new Dimension(800, 300)); 
          frame.getContentPane().add(textLabel, BorderLayout.CENTER); 
          frame.setLocationRelativeTo(null); 
          frame.pack(); 
          frame.setVisible(true); 
          
          JLabel textLabel2 = new JLabel("--- Steps Today!",SwingConstants.CENTER); 
          textLabel2.setPreferredSize(new Dimension(800, 350)); 
          frame.getContentPane().add(textLabel2, BorderLayout.CENTER); 
          frame.setLocationRelativeTo(textLabel); 
          frame.pack(); 
          frame.setVisible(true);
          
          JLabel textLabel3 = new JLabel("Total Distance Walked",SwingConstants.CENTER); 
          textLabel3.setPreferredSize(new Dimension(800,450)); 
          frame.getContentPane().add(textLabel3, BorderLayout.CENTER); 
          frame.setLocationRelativeTo(textLabel2); 
          frame.pack(); 
          frame.setVisible(true);
          
          JLabel textLabel4 = new JLabel("--- Kilometres",SwingConstants.CENTER); 
          textLabel4.setPreferredSize(new Dimension(800, 500)); 
          frame.getContentPane().add(textLabel4, BorderLayout.CENTER); 
          frame.setLocationRelativeTo(textLabel3); 
          frame.pack(); 
          frame.setVisible(true);
          
          JLabel textLabel5 = new JLabel(" “All truly great thoughts are conceived while walking.” ",SwingConstants.CENTER); 
          textLabel5.setPreferredSize(new Dimension(800, 600)); 
          frame.getContentPane().add(textLabel5, BorderLayout.CENTER); 
          frame.setLocationRelativeTo(textLabel4); 
          frame.pack(); 
          frame.setVisible(true);
          
          JLabel textLabel6 = new JLabel(" - Friedrich Nietzsche, Twilight of the Idols ",SwingConstants.CENTER); 
          textLabel6.setPreferredSize(new Dimension(800, 650)); 
          frame.getContentPane().add(textLabel6, BorderLayout.CENTER); 
          frame.setLocationRelativeTo(textLabel5); 
          frame.pack(); 
          frame.setVisible(true);
          
          JPanel panel = new JPanel();
          frame.add(panel);
          JButton button = new JButton("Global Leaderboards");
          panel.add(button);
          button.addActionListener (new Action1());

          JButton button2 = new JButton("User Profile");
          panel.add(button2);
          button2.addActionListener (new Action2());}
        
        


            
        
      }
       else {
         message.setText(" Invalid user.. ");
       }
         
}

}

然而，当我按下用户配置文件按钮时，只显示框架，而不显示标签和文本字段。 两个都在类，我设法让全球排行榜工作（不包括在这里），只是似乎不能让用户Proflie正常工作。

public class Action2 extends JFrame implements ActionListener {


    public Action2() {
    setLayout(new GridLayout(11, 5, 5, 5));
    add(new JLabel("Nickname"));
    add(new JTextField(10));
    add(new JLabel("Age"));
    add(new JTextField(3));
    add(new JLabel("Gender"));
    add(new JTextField(8));
    add(new JLabel("Height"));
    add(new JTextField(4));
    add(new JLabel("Weight"));
    add(new JTextField(4));
    add(new JLabel("Your Goal"));
    add(new JRadioButton("Easy"));
    add(new JRadioButton("Intermediate"));
    add(new JRadioButton("Hard"));
    add(new JButton("Update Profile"));

    
    
}
    
    public void actionPerformed(ActionEvent e) {
        

        Action2 frame = new Action2();
        frame.setTitle("Profile");
        frame.setSize(400,400);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

}

我能得到的任何帮助都非常感激。