Java Swing中从JOptionPane启动新窗体的教程

import javax.swing.JOptionPane;

public class AppLauncher {
    private static final String SETTINGS = "Settings";
    private static final String CLOSE = "Close";

    public static void main(String[] args) {
        // 弹出选项对话框
        int choice = JOptionPane.showOptionDialog(null,
                                                  "Choose option",
                                                  "Option dialog",
                                                  JOptionPane.YES_NO_OPTION,
                                                  JOptionPane.QUESTION_MESSAGE,
                                                  null,
                                                  new String[]{SETTINGS, CLOSE},
                                                  SETTINGS);

        // 根据用户选择进行操作
        if (choice == JOptionPane.YES_OPTION) { // 对应 "Settings" 按钮
            // 在此处启动新的JFrame
            System.out.println("Settings chosen. Launching application...");
            // ... 后续代码将在此处调用新窗体
        } else { // 对应 "Close" 按钮或对话框关闭
            System.out.println("Close chosen or dialog closed. Exiting.");
            System.exit(0);
        }
    }
}

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.util.Locale;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
import javax.swing.Timer; // 注意：这里是javax.swing.Timer
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class TimerApplication {
    private static final String  CLOSE = "Close";
    private static final String  SETTINGS = "Settings";

    private JButton  startButton;
    private JButton  stopButton;
    private JFrame  frame;
    private JLabel  theWatch;
    private Timer  swingTimer; // 使用javax.swing.Timer

    public TimerApplication() {
        // 初始化Swing Timer，每1000毫秒（1秒）触发一次
        // this::updateTimer 是方法引用，等同于 new ActionListener() { @Override public void actionPerformed(ActionEvent e) { updateTimer(e); } }
        swingTimer = new Timer(1000, this::updateTimer);
        swingTimer.setInitialDelay(0); // 立即激活
    }

    private void buildAndDisplayGui() {
        frame = new JFrame("Timer App");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // 创建显示时间的标签
        theWatch = new JLabel(getCurrentTime(), SwingConstants.CENTER);
        theWatch.setBorder(BorderFactory.createEmptyBorder(30, 30, 30, 30)); // 添加边距
        theWatch.setForeground(Color.red); // 初始颜色为红色
        theWatch.setToolTipText("Timer is currently stopped."); // 停止时显示提示
        frame.add(theWatch, BorderLayout.CENTER);

        // 创建按钮面板
        frame.add(createButtons(), BorderLayout.PAGE_END);

        frame.pack(); // 根据组件的首选大小调整窗口大小
        frame.setLocationByPlatform(true); // 窗口位置由平台决定
        frame.setVisible(true); // 显示窗口
    }

    private JPanel createButtons() {
        JPanel panel = new JPanel();
        startButton = new JButton("Start");
        startButton.setMnemonic(KeyEvent.VK_A); // 设置快捷键 Alt+A
        startButton.setToolTipText("Starts the timer.");
        startButton.addActionListener(this::startTimer);
        panel.add(startButton);

        stopButton = new JButton("Stop");
        stopButton.setMnemonic(KeyEvent.VK_O); // 设置快捷键 Alt+O
        stopButton.setToolTipText("Stops the timer.");
        stopButton.addActionListener(this::stopTimer);
        stopButton.setEnabled(false); // 初始状态下停止按钮不可用
        panel.add(stopButton);
        return panel;
    }

    // 获取当前时间并格式化
    private String getCurrentTime() {
        return LocalTime.now().format(DateTimeFormatter.ofPattern("HH:mm:ss", Locale.ENGLISH));
    }

    // 启动计时器
    private void startTimer(ActionEvent event) {
        theWatch.setToolTipText(null);
        theWatch.setForeground(Color.black); // 启动时切换颜色
        startButton.setEnabled(false);
        swingTimer.start();
        stopButton.setEnabled(true);
    }

    // 停止计时器
    private void stopTimer(ActionEvent event) {
        swingTimer.stop();
        theWatch.setForeground(Color.red); // 停止时切换颜色
        theWatch.setToolTipText("Timer is currently stopped.");
        startButton.setEnabled(true);
        stopButton.setEnabled(false);
    }

    // 更新时间显示
    private void updateTimer(ActionEvent event) {
        theWatch.setText(getCurrentTime());
    }

    public static void main(String[] args) {
        int choice = JOptionPane.showOptionDialog(null,
                                                  "Choose option",
                                                  "Option dialog",
                                                  JOptionPane.YES_NO_OPTION,
                                                  JOptionPane.QUESTION_MESSAGE,
                                                  null,
                                                  new String[]{SETTINGS, CLOSE},
                                                  SETTINGS);
        if (choice == JOptionPane.YES_OPTION) {
            // 设置系统默认外观，提升用户体验
            String slaf = UIManager.getSystemLookAndFeelClassName();
            try {
                UIManager.setLookAndFeel(slaf);
            }
            catch (ClassNotFoundException |
                   IllegalAccessException |
                   InstantiationException |
                   UnsupportedLookAndFeelException x) {
                System.out.println("WARNING (ignored): Failed to set [System] look-and-feel.");
            }
            // 确保Swing UI操作在事件调度线程上执行
            EventQueue.invokeLater(() -> new TimerApplication().buildAndDisplayGui());
        }
        else {
            System.exit(0);
        }
    }
}

// 确保Swing UI操作在事件调度线程上执行
EventQueue.invokeLater(() -> new TimerApplication().buildAndDisplayGui());