java语言GUI编程之Anoymous匿名类2

import java.awt.*;import java.awt.event.*;

public class TestAnoymous2 { Frame f = new Frame("测试匿名类"); TextField tf = new TextField(10); Button b1 = new Button("Start"); private int i = 0;  public TestAnoymous2() {  f.add(b1, "North");  f.add(tf, BorderLayout.SOUTH);    b1.addActionListener(new ActionListener() {   public void actionPerformed(ActionEvent e) {    tf.setText(e.getActionCommand() + (++i));   }  });  f.addWindowListener(new WindowAdapter() {   public void windowClosing(WindowEvent e) {    System.exit(0);   }  });  f.setSize(300, 300);  f.setVisible(true); }  public static void main(String[] args) {  new TestAnoymous2(); } }