textareademo.java

我在学习JAVA的讲义

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

public class TextAreaDemo extends JFrame {
   private JTextArea t1, t2;
   private JButton copy;

   public TextAreaDemo() 
   {
      super( "TextArea Demo" );

      Box b = Box.createHorizontalBox();

      String s = "This is a demo string to\n" +
                 "illustrate copying text\n" +
                 "from one TextArea to \n" +
                 "another TextArea using an\n"+
                 "external event\n";

      t1 = new JTextArea( s, 10, 15 );
      b.add( new JScrollPane( t1 ) );

      copy = new JButton( "Copy >>>" );
      copy.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               t2.setText( t1.getSelectedText() );
            }
         }
      );
      b.add( copy );

      t2 = new JTextArea( 10, 15 );
      t2.setEditable( false );
      b.add( new JScrollPane( t2 ) );

      Container c = getContentPane();
      c.add( b );    // Box placed in BorderLayout.CENTER
      setSize( 425, 200 );
      show();
   }

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

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