debug13_3.java

北京大学出版社的

package questions.c13;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Debug13_3 extends JFrame {
   public Debug13_3( String titleText ) {
      super( titleText );
      addWindowListener( new WindowAdapter() {
            public void windowClosing( WindowEvent e ) {
               e.getWindow().dispose();
               System.exit( 0 );
            }
         }
      );
      JButton[] buttons = new JButton[9];
      for( int i=0; i<buttons.length; i++ ) {
         buttons[i]
            = new JButton( String.valueOf( i+1 ) );
         add( buttons[i] );
      }
      pack();
      setVisible( true );
   }
   public static void main( String[] args ) {
      new Debug13_3( "Debug Question" );
   }
}