menuexample.java

Java程序设计实验与实训源代码经典的JAVA学习教材

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


class MenuExample{
	public static void main(String[] args) {
		MyFrameSeven myFrame=new MyFrameSeven();
		myFrame.show();
	}
}

class MyFrameSeven extends JFrame implements ActionListener{
	private JLabel myLabel;
	private JMenuItem newItem;
	private JMenuItem openItem;
	private JMenuItem exitItem;
	
	MyFrameSeven(){
		JMenuBar menuBar = new JMenuBar();
		setJMenuBar(menuBar);
		JMenu fileMenu = new JMenu("文件(F)");
		fileMenu.setMnemonic('F');
		
		newItem=new JMenuItem("新建");
		newItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, InputEvent.CTRL_MASK));
		newItem.addActionListener(this);
 		openItem=new JMenuItem("打开");
 		openItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, InputEvent.CTRL_MASK));
 		openItem.addActionListener(this);
		exitItem=new JMenuItem("退出");
		exitItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_E, InputEvent.CTRL_MASK));
		exitItem.addActionListener(this);
		
		fileMenu.add(newItem);
		fileMenu.add(openItem);
		fileMenu.addSeparator();
		fileMenu.add(exitItem);
		
		menuBar.add(fileMenu);

		
		Container myContentPane=getContentPane();
		JPanel textPanel=new JPanel();
		myLabel=new JLabel("");
		textPanel.add(myLabel);
		myContentPane.add(textPanel);
			
		
		setSize(400,200);
		addWindowListener(new QuitWindow());
	}
	
	public void actionPerformed(ActionEvent event){
		if(event.getSource()==newItem)
			myLabel.setText("你选了"+newItem.getText()+"菜单项");
		if(event.getSource()==openItem)
			myLabel.setText("你选了"+openItem.getText()+"菜单项");
		if(event.getSource()==exitItem){
			int selection = JOptionPane.showConfirmDialog(this,
				"你确定退出?", "退出", 
				JOptionPane.OK_CANCEL_OPTION,
				JOptionPane.WARNING_MESSAGE);
 			if(selection == JOptionPane.OK_OPTION){
				System.exit(0);
			}
		}

		
	}
}

class QuitWindow extends WindowAdapter{
	public void windowClosing(WindowEvent e){
		System.exit(0);
	}
}