java例程练习（TextField）

import java.awt.*; import java.awt.event.*; public class TestTFAction { public static void main(String[] args) { new TFFrame(); } } class TFFrame extends Frame { TFFrame() { TextField tf = new TextField(); add(tf); tf.addActionListener(new TFActionListener()); tf.setEchoChar('*'); pack(); setVisible(true); } } class TFActionListener implements ActionListener { public void actionPerformed(ActionEvent e) { TextField tf = (TextField) e.getSource(); System.out.println(tf.getText()); tf.setText(""); } }