countdowntester.java

Java程序设计技巧与开发实例附书源代码。

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

public class CountDownTester
    extends Frame
    implements ActionListener {
  private Button start = new Button("Start");
  private Button show = new Button("Show");
  private TextField display = new TextField(25);
  private CountDown count = new CountDown(show, 25);

  private class WindowCloser
      extends WindowAdapter {
    public void windowClosing(WindowEvent we) {
      System.exit(0);
    }
  }

  public CountDownTester() {
    super("CountDown Tester");
    setLayout(new FlowLayout());
    add(start);
    add(show);
    add(display);
    show.addActionListener(this);
    start.addActionListener(this);
    count.addActionListener(this);
    addWindowListener(new WindowCloser());
    pack();
    show();
  }

  public void actionPerformed(ActionEvent e) {
    if (e.getSource() == start) {
      count.startCounting();
    }
    else if (e.getSource() == show) {
      display.setText("事件来自于：" + e.getActionCommand());
    }
  }

  public static void main(String args[]) {
    CountDownTester c = new CountDownTester();
  }
}