checkboxexample.java

中国水利水电出版社java程序设计教程,附源码

//CheckBoxExample.java

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

public class CheckBoxExample
{  
	public static void main(String[] args)
	{  
		CheckBoxFrame frame = new CheckBoxFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.show();
	}
}

class CheckBoxFrame extends JFrame
{
	public CheckBoxFrame()
	{
		setTitle("CheckBoxExample");
		setSize(WIDTH, HEIGHT);

		Container contentPane = getContentPane();

		//新建标签
		myLabel = new JLabel(checkedLabel, JLabel.CENTER);
		myLabel.setFont(new Font("Serif", Font.PLAIN, 12));
		contentPane.add(myLabel, BorderLayout.CENTER);

		//建立容器面板
		checkPanel = new JPanel();

		//新建复选框
		boldCheck = new JCheckBox("Bold");
		
		//增加事件监听器
		boldCheck.addActionListener(new checkListener());

		italicCheck = new JCheckBox("Italic");
		italicCheck.addActionListener(new checkListener());

		checkPanel.add(boldCheck);
		checkPanel.add(italicCheck);

		contentPane.add(checkPanel, BorderLayout.SOUTH);
	}

	//两个复选框共用的事件监听器
	private class checkListener
		implements ActionListener
	{
		public void actionPerformed(ActionEvent event)
		{
			int fontStyle = 0;
			
			//判断复选框是否被选取
			if(boldCheck.isSelected())
				fontStyle += Font.BOLD;
			if(italicCheck.isSelected())
				fontStyle += Font.ITALIC;

			myLabel.setFont(new Font("Serif", fontStyle , 12));
		}
	}

	public static final int WIDTH = 200;
	public static final int HEIGHT = 140;
	public static final String checkedLabel="You choosed: ";

	private JLabel myLabel;
	private JCheckBox boldCheck;
	private JCheckBox italicCheck;
	private JPanel checkPanel;
}