11.粗体，斜体复选框，改变字体样式

效果：

package com.lvshitech.gui;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.JApplet;
import javax.swing.JCheckBox;
import javax.swing.JTextField;

@SuppressWarnings("serial")
public class JCheckBoxDemo extends JApplet implements ItemListener {

	private JTextField t;
	private JCheckBox bold, italic;
	
	public void init() {
		Container container = getContentPane();
		
		// 字体对象
		t = new JTextField("观察这里文字字形的变化", 40);
		t.setFont(new Font("Serif", Font.PLAIN, 30));
		container.add(t, BorderLayout.NORTH);
		
		// 粗体对象
		bold = new JCheckBox("粗体Bold");
		bold.addItemListener(this);
		container.add(bold, BorderLayout.CENTER);
		
		// 斜体对象
		italic = new JCheckBox("斜体Italic");
		italic.addItemListener(this);
		container.add(italic, BorderLayout.SOUTH);
	}
	
	@Override
	public void itemStateChanged(ItemEvent e) {
		int b = bold.isSelected() ? Font.BOLD : Font.PLAIN;
		int i = italic.isSelected() ? Font.ITALIC : Font.PLAIN;
		t.setFont(new Font("Serif", b+i, 30));
	}

}