如何在不同类的另一个方法中使用一个方法的变量？

Question

我想知道是否可以将变量user2和pass2（它们都位于类register中的showWindow()方法中）用于类logindemo中的showWindow()方法，以便在register类中输入的用户名和密码将与logindemo类中的输入匹配。

public class LoginDemo 

    public static void showWindow() {
        JPanel panel = new JPanel();
        JFrame frame = new JFrame("Log in/Sign up ");
        frame.setSize(300, 180);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(panel);

        panel.setLayout(null);

        userLabel = new JLabel("USERNAME");
        userLabel.setBounds(10, 10, 80, 25);
        panel.add(userLabel);

        userText = new JTextField(20);
        userText.setBounds(100, 10, 160, 25);
        panel.add(userText);

        passwordLabel = new JLabel("PASSWORD");
        passwordLabel.setBounds(10, 40, 80, 25);
        panel.add(passwordLabel);

        passwordText = new JPasswordField(20);
        passwordText.setBounds(100, 40, 160, 25);
        panel.add(passwordText);

        button = new JButton("LOG-IN");
        button.setBounds(10, 80, 80, 25);
        button.addActionListener(new LoginDemo());
        panel.add(button);

        success = new JLabel("");
        success.setBounds(10, 110, 300, 25);
        panel.add(success);

        JButton registerButton = new JButton("CREATE ACCOUNT");
        registerButton.setBounds(130, 80, 150, 25);
        panel.add(registerButton);
        registerButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                frame.setVisible(false);
                Register w2 = new Register();
                w2.showWindow();
            }
        });

        frame.setVisible(true);
    }

    public void actionPerformed(ActionEvent e){

        Register w2 = new Register();

        String user = userText.getText();
        String password = passwordText.getText();


        if(user.equals(w2.user2) && password.equals(w2.pass2))
        {
            JOptionPane.showMessageDialog(null,"Log in Successful!");
        }
        else
        {

            JOptionPane.showMessageDialog(null,"Invalid Login Details" + " \nLogin Error ");
        }

    }
}

public class Register
 

        label1 = new JLabel("Username");
        label1.setBounds(20, 50, 100, 20);
        frame.add(label1);

        t1 = new JTextField();
        t1.setBounds(130, 50, 100, 20);
        frame.add(t1);

        label2 = new JLabel("Password");
        label2.setBounds(20, 100, 100, 20);
        frame.add(label2);

        t2 = new JPasswordField();
        t2.setBounds(130, 100, 100, 20);
        frame.add(t2);

        submit = new JButton("Submit");
        submit.setBounds(70, 350, 80, 20);
        frame.add(submit);
        submit.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                LoginDemo w1 = new LoginDemo();
                String user2 = t1.getText();
                String pass2 = t2.getText();
                w1.showWindow();
                frame.setVisible(false);


            }
        });



        back = new JButton("Back");
        back.setBounds(250, 350, 80, 20);
        frame.add(back);
        back.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                LoginDemo w1 = new LoginDemo();
                w1.showWindow();
                frame.setVisible(false);



            }
        });


    }

}

Answer 1

同意@Federico的评论。如果要实现预期的行为，需要在Register类中添加两个私有成员变量，并为它们添加getter方法。然后您可以从actionPerformed方法分配那些变量值，并使用getter获取值并在LoginDemo中进行比较。但您的代码肯定需要大量的重构。