jcheckboxdemo.java

来自「本java源程序包括了大量的学习程序（共27章）方便大家学习」· Java 代码 · 共 67 行

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class JCheckBoxDemo extends JFrame 
{
    private JLabel label;
    private JCheckBox bold, italic;
		public JCheckBoxDemo() 
		{
			super("复选框");
			setSize(300, 100);  
			try
			{ //设置外观
				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
			}catch(Exception e){}		
        //获取内容面板
			Container container = getContentPane();
			//设置内容面板的布局管理器
			container.setLayout(new FlowLayout());
			//设置内容面板的背景色
			container.setBackground(Color.YELLOW);
		
			//创建标签对象，并设置字体
			label = new JLabel("请注意观察宋体的变化");
			label.setFont(new Font("Serif", Font.PLAIN, 14));
			container.add(label);
		
			//创建复选框
			bold = new JCheckBox("粗体");
			italic = new JCheckBox("斜体");
			bold.setFont(new Font("Serif", Font.PLAIN, 12));
			italic.setFont(new Font("Serif", Font.PLAIN, 12));
			bold.setBackground(Color.YELLOW);
			italic.setBackground(Color.YELLOW);
		
			//注册监听器
			CheckBoxHandler handler = new CheckBoxHandler();
			bold.addItemListener(handler);
			italic.addItemListener(handler);
		
			container.add(bold);
			container.add(italic);
		
			setVisible(true);
			setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		}
	
	public static void main(String[] args) 
	{
		JCheckBoxDemo application = new JCheckBoxDemo();
	}
	
	private class CheckBoxHandler implements ItemListener
	{
		private int valBold = Font.PLAIN;
		private int valItalic = Font.PLAIN;
		public void itemStateChanged(ItemEvent event)
		{
			if(event.getSource() == bold)
				valBold = bold.isSelected()? Font.BOLD : Font.PLAIN;
			if(event.getSource() == italic)
				valItalic = bold.isSelected()? Font.ITALIC : Font.PLAIN;
			label.setFont(new Font("Serif", valBold + valItalic, 14));
		}
	}
}