debug13_5.java

北京大学出版社的

package questions.c13;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
// extend the Frame class
public class Debug13_5 extends JFrame {
   public Debug13_5( String titleText ) {
      super( titleText );
      addWindowListener( new WindowAdapter() {
            public void windowClosing( WindowEvent e ) {
               e.getWindow().dispose();
               System.exit( 0 );
            }
         }
      );
      setSize( 500, 300 );
      setVisible( true );
   }
   public void paintComponent( Graphics g ) {
      int squareSize = 30;
      Dimension d = getSize();
      g.setColor( Color.white );
      g.fillRect( 0, 0, d.width, d.height );
      g.setColor( Color.black );
      for( int y=0; y<d.height; y+=squareSize*2 ) {
         for( int x=0; x<d.width; x+=squareSize*2 ) {
            g.fillRect( x, y,
                        squareSize, squareSize );
         }
      }
   }
   public static void main( String[] args ) {
      new Debug13_5( "Debug Question" );
   }
}