invoceventdemo.java

《java事件处理指南》一书的代码,好东西

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

public class InvocEventDemo extends JFrame implements ActionListener
{
   private JLabel label;
   private JButton button;
   private JPanel southPanel, centerPanel;

   public InvocEventDemo()
   {
      button = new JButton("Time");
      button.setBorder(BorderFactory.createRaisedBevelBorder());
      button.addActionListener(this);

      label = new JLabel("");
      label.setFont(new Font("Serif", Font.PLAIN, 12));
      label.setForeground(Color.black);

      southPanel = new JPanel();
      southPanel.add(button);

      centerPanel = new JPanel();
      centerPanel.add(label);

      getContentPane().add(southPanel, BorderLayout.SOUTH);
      getContentPane().add(centerPanel, BorderLayout.CENTER);

      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setBounds(100, 100, 300, 200);
      setVisible(true);
   }

/*  When the JButton is pressed, an ActionEvent is generated and   */
/*  sent to the actionPerformed() method.  This method creates an  */
/*  InvocationEvent object which is then dispatched.  The event    */
/*  calls the run() method of the GetTime class which displays     */
/*  the current time.                                              */

   public void actionPerformed(ActionEvent event)
   {
      InvocationEvent ie = 
               new InvocationEvent(this, new GetTime());
      ie.dispatch();
   }

   class GetTime implements Runnable
   {
      public void run()
      {
           Date d = new Date();
           label.setText(d.toString());
           centerPanel.invalidate();
           centerPanel.validate();
      }
   }

   public static void main(String args[])
   {
      InvocEventDemo demo = new InvocEventDemo();
   }
}