borderlayoutdemo.java

经典的<<C how to program>一书第三版的例程。非常适合于C的初学者。

// Fig. 29.18: BorderLayoutDemo.java
// Demonstrating BorderLayout.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class BorderLayoutDemo extends JFrame
                              implements ActionListener {
   private JButton b[];
   private String names[] =
      { "Hide North", "Hide South", "Hide East",
        "Hide West", "Hide Center" };
   private BorderLayout layout;

   public BorderLayoutDemo()
   {
      super( "BorderLayout Demo" );

      layout = new BorderLayout( 5, 5 );

      Container c = getContentPane();
      c.setLayout( layout );

      // instantiate button objects
      b = new JButton[ names.length ];

      for ( int i = 0; i < names.length; i++ ) {
         b[ i ] = new JButton( names[ i ] );
         b[ i ].addActionListener( this );
      }

      // order not important
      c.add( b[ 0 ], BorderLayout.NORTH );  // North position
      c.add( b[ 1 ], BorderLayout.SOUTH );  // South position
      c.add( b[ 2 ], BorderLayout.EAST );   // East position
      c.add( b[ 3 ], BorderLayout.WEST );   // West position
      c.add( b[ 4 ], BorderLayout.CENTER ); // Center position

      setSize( 300, 200 );
      show();
   }            

   public void actionPerformed( ActionEvent e )
   {
      for ( int i = 0; i < b.length; i++ ) 
         if ( e.getSource() == b[ i ] )
            b[ i ].setVisible( false );
         else
            b[ i ].setVisible( true );

      // re-layout the content pane
      layout.layoutContainer( getContentPane() );
   }

   public static void main( String args[] )
   { 
      BorderLayoutDemo app = new BorderLayoutDemo();

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

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 * (C) Copyright 2000 by Deitel & Associates, Inc. and Prentice Hall.     *
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