如何通过JComboBox选择打开另一个JFrame？

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

public class MainFrame extends JFrame {
    private JComboBox<String> comboBox;

    public MainFrame() {
        // 设置主窗口的属性
        setTitle("主窗口");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 200);
        setLocationRelativeTo(null);

        // 创建一个JComboBox对象，并添加选项
        comboBox = new JComboBox<>();
        comboBox.addItem("选项1");
        comboBox.addItem("选项2");
        comboBox.addItem("选项3");

        // 添加选择事件的监听器
        comboBox.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // 获取选择的选项
                String selectedOption = (String) comboBox.getSelectedItem();

                // 根据选择的选项创建新的JFrame对象
                if (selectedOption.equals("选项1")) {
                    JFrame newFrame = new JFrame("新窗口1");
                    newFrame.setSize(200, 150);
                    newFrame.setLocationRelativeTo(null);
                    newFrame.setVisible(true);
                } else if (selectedOption.equals("选项2")) {
                    JFrame newFrame = new JFrame("新窗口2");
                    newFrame.setSize(200, 150);
                    newFrame.setLocationRelativeTo(null);
                    newFrame.setVisible(true);
                } else if (selectedOption.equals("选项3")) {
                    JFrame newFrame = new JFrame("新窗口3");
                    newFrame.setSize(200, 150);
                    newFrame.setLocationRelativeTo(null);
                    newFrame.setVisible(true);
                }
            }
        });

        // 将JComboBox添加到主窗口中
        getContentPane().add(comboBox);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                MainFrame mainFrame = new MainFrame();
                mainFrame.setVisible(true);
            }
        });
    }
}