topleveldemo.java

java应用开发详解

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

public class TopLevelDemo {
    public static void main(String s[]) {
    	
    	//引入顶级容器类JFrame
        JFrame frame = new JFrame("TopLevelDemo");

        //关闭窗口事件
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

	//添加一个显示标签
        JLabel yellowLabel = new JLabel("");
        
        //设置标签的显示属性为true
        yellowLabel.setOpaque(true);
        
        //设置标签的背景颜色为黄色
        yellowLabel.setBackground(Color.yellow);
        
        //设置标签的大小
        yellowLabel.setPreferredSize(new Dimension(200, 180));

        //添加一个菜单栏
        JMenuBar cyanMenuBar = new JMenuBar();
        cyanMenuBar.setOpaque(true);
        cyanMenuBar.setBackground(Color.cyan);
        cyanMenuBar.setPreferredSize(new Dimension(200, 20));

        //添加菜单
        frame.setJMenuBar(cyanMenuBar);
        
        //返回一个Root panel，添加黄色标签
        frame.getContentPane().add(yellowLabel, BorderLayout.CENTER);

        frame.pack();
        frame.setVisible(true);
    }

}