Java Swing 自定义JOptionPane

运行后的样式

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;public class demoB {public static void main(String[] args) {SwingUtilities.invokeLater(() -> {JFrame jf = new JFrameDemo();jf.setVisible(true);});}static class JFrameDemo extends JFrame {private JButton button;public JFrameDemo() {setTitle("主窗口");setSize(400, 300);setDefaultCloseOperation(EXIT_ON_CLOSE);setLocationRelativeTo(null);button = new JButton("打开对话框");button.addActionListener(new DialogListener());getContentPane().add(button, BorderLayout.CENTER);}public JButton getJButton() {return button;}}static class DialogListener implements ActionListener {@Overridepublic void actionPerformed(ActionEvent e) {// 主面板（设置内边距）JPanel mainPanel = new JPanel(new GridLayout(2, 1, 5, 10)); // 行间距10像素mainPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10)); // 外边距// 创建两行输入区域mainPanel.add(createInputRow("按钮1"));mainPanel.add(createInputRow("按钮2"));// 显示对话框JOptionPane.showOptionDialog(null,mainPanel,"标题",JOptionPane.DEFAULT_OPTION,JOptionPane.PLAIN_MESSAGE,null,new Object[]{},  // 必须空数组null);}// 创建单行布局（核心修改部分）private JPanel createInputRow(String buttonText) {JPanel panel = new JPanel(new BorderLayout(10, 0)); // 水平间距10像素JTextField textField = new JTextField();textField.setPreferredSize(new Dimension(200, 30)); // 固定高度30JButton button = new JButton(buttonText);button.setPreferredSize(new Dimension(80, 30));    // 固定高度30panel.add(textField, BorderLayout.CENTER);panel.add(button, BorderLayout.EAST);return panel;}}
}