20.对话框

效果：

package com.lvshitech.gui;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;

public class JOptionPaneDemo {
	public JFrame aFrame;
	public JButton aButton;
	public JOptionPane anOptionPane;
	static JLabel aLabel;
	
	public JOptionPaneDemo() {
		aFrame = new JFrame("使用JOptionPane");
		Container container = aFrame.getContentPane();
		
		aButton = new JButton("显示对话框");
		aLabel = new JLabel("您作出的选择是：", JLabel.CENTER);
		aButton.addActionListener(new OptionListener());
		anOptionPane = new JOptionPane();
		
		aFrame.setSize(300, 200);
		container.add(aButton, BorderLayout.NORTH);
		container.add(aLabel, BorderLayout.SOUTH);
		aFrame.setVisible(true);
		aFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	
	// 点击按钮触发事件
	public class OptionListener implements ActionListener {
		@Override
		public void actionPerformed(ActionEvent e) {
			String []choices = {"喜欢", "不喜欢"};
			int n = anOptionPane.showOptionDialog(aFrame, "您喜欢音乐吗？", "请选择", 
					JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, 
					null, choices, choices[0]);
			if (n == 0) {
				JOptionPaneDemo.aLabel.setText("您作出的选择是：" + choices[0] + "音乐");
			} else {
				JOptionPaneDemo.aLabel.setText("您作出的选择是：" + choices[1] + "音乐");
			}
		}
	}
	
	public static void main(String[] args) {
		new JOptionPaneDemo();
	}
}