checkboxtest.java

这个是Java的swing相关的典型的源码

/**
   @version 1.32 2004-05-05
   @author Cay Horstmann
*/

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

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

/**
   A frame with a sample text label and check boxes for
   selecting font attributes.
*/
class CheckBoxFrame extends JFrame 
{  
   public CheckBoxFrame()
   {  
      setTitle("CheckBoxTest");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      // add the sample text label

      label = new JLabel("The quick brown fox jumps over the lazy dog.");
      label.setFont(new Font("Serif", Font.PLAIN, FONTSIZE));
      add(label, BorderLayout.CENTER);

      // this listener sets the font attribute of
      // the label to the check box state

      ActionListener listener = new 
         ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               int mode = 0;
               if (bold.isSelected()) mode += Font.BOLD; 
               if (italic.isSelected()) mode += Font.ITALIC;
               label.setFont(new Font("Serif", mode, FONTSIZE));
            }
         };

      // add the check boxes

      JPanel buttonPanel = new JPanel();

      bold = new JCheckBox("Bold");    
      bold.addActionListener(listener);
      buttonPanel.add(bold);

      italic = new JCheckBox("Italic");    
      italic.addActionListener(listener);
      buttonPanel.add(italic);

      add(buttonPanel, BorderLayout.SOUTH);
   }
   
   public static final int DEFAULT_WIDTH = 300;
   public static final int DEFAULT_HEIGHT = 200;  

   private JLabel label;
   private JCheckBox bold;
   private JCheckBox italic;        

   private static final int FONTSIZE = 12;
}