java - 访问 JFrame 中的变量

Question

如果我有以下 Java 代码:

import javax.swing.JFrame;
class GuessMyNumber extends JFrame {
    public static void main(String[] args) {
        InputBox box = new InputBox("Guess a number between 1 and 100:");
        box.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        box.setSize(360, 360);
        box.setVisible(true);
    }
}

输入框类:

import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class InputBox extends JFrame {
    private JLabel text1;
    private JTextField textField1;
    public InputBox(String prompt) {
        super("Guess My Number");
        setLayout(new FlowLayout());
        text1 = new JLabel(prompt);
        add(text1);
        textField1 = new JTextField(20);
        add(textField1);
        Handler handler = new Handler();
        textField1.addActionListener(handler);
    }
    private class Handler implements ActionListener {
        String in = "";
        public void actionPerformed(ActionEvent event) {
            if (event.getSource() == textField1) {
                in = event.getActionCommand();
            }
        }
    }
}

如何从主类访问in？我是 Java GUI 的绝对初学者，所以请不要太严厉!

谢谢

Answer 1

将 in 的声明移至 InputBox 类。您可以将框架类型设置为模态(setModal(true))，并从ActionListener调用dispose()方法，然后您的主线程将阻塞直到用户输入一些数字。