小编die*_*UET的帖子

我有一个简单的Java Swing表单JTextField,我JTextField通过getText()方法得到了值,但我不能将它用于主程序.你能帮我解决什么问题以及如何解决？这是我的代码:

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class Login {
private String name;

public Login() {
    JFrame main = new JFrame("LOGIN");
    main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    main.setResizable(false);
    main.setLayout(null);
    main.setPreferredSize(new Dimension(200, 300));
    main.setLocation(400, 200);

    // Heading: LOGIN
    JLabel heading = new JLabel("LOGIN");
    heading.setBounds(80, 20, 50, 20);
    main.add(heading);

    // Label Username
    JLabel username_label = new JLabel("username: ");
    username_label.setBounds(5, 70, 80, 20);
    main.add(username_label);
    // Textfield Username
    final JTextField username_field = new JTextField();
    username_field.setBounds(70, 70, 120, 20); …