建立了一个按钮,按钮上自动更新显示数字。
</pre><pre name="code" class="java">package com.demo; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.*; import javax.swing.*; public class demo extends JFrame { private int delay; private int count; private JButton jbt = new JButton(); public demo(){ JPanel panel = new JPanel(); int delay = 1000; //milliseconds panel.add(jbt); Timer timer = new Timer(delay, new TimerListener()); timer.start(); this.add(panel); } private class TimerListener implements ActionListener{ @Override public void actionPerformed(ActionEvent e) { count++; jbt.setText(""+count); jbt.repaint(); } } public static void main(String[] args) { demo mydemo = new demo(); mydemo.setTitle("MyDemo"); mydemo.setSize(200, 200); mydemo.setLocationRelativeTo(null); mydemo.setVisible(true); mydemo.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } }结果如下:按钮上可以自动更新数字,以此为基础可以衍生出倒计时器。