checkboxdemo.java

java 完全探索的随书源码

// CheckBoxDemo.java

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;

class CheckBoxDemo extends JFrame implements ActionListener
{
   CheckBoxDemo (String title)
   {
      super (title);

      addWindowListener (new WindowAdapter ()
                         {
                             public void windowClosing (WindowEvent e)
                             {
                                System.exit (0);
                             }
                         });

      ButtonGroup bg = new ButtonGroup ();

      JCheckBox north = new JCheckBox ("North");
      north.setMnemonic ('o');
      north.addActionListener (this);
      bg.add (north);
      getContentPane ().add (north, BorderLayout.NORTH);

      JCheckBox west = new JCheckBox ("West", true);
      west.addActionListener (this);
      bg.add (west);
      getContentPane ().add (west, BorderLayout.WEST);

      JCheckBox center = new JCheckBox ("Center");
      center.addActionListener (this);
//      bg.add (center);
      getContentPane ().add (center, BorderLayout.CENTER);

      JCheckBox east = new JCheckBox ("East");
      east.addActionListener (this);
      bg.add (east);
      getContentPane ().add (east, BorderLayout.EAST);

      JCheckBox south = new JCheckBox ("South",
                                       new ImageIcon ("bullet.gif"));
      south.addActionListener (this);
      bg.add (south);
      getContentPane ().add (south, BorderLayout.SOUTH);

      pack ();
      setVisible (true);
   }

   public void actionPerformed (ActionEvent e)
   {
      System.out.println (e.getActionCommand ());
   }

   public static void main (String [] args)
   {
      new CheckBoxDemo ("CheckBox Demo");
   }
}