Question

JAVA需要一条秒表计时器代码

1.需要计时器窗口有置顶功能
2.能显示时分秒
3.没有“清零”按钮，仅有开始和暂停按钮，并且能使用快捷键使用。

Answer 1

好吧，已看到你的评论,我在这里再回答一次：

1）你所说的置顶如果是属于悬浮窗效果，那么JFrame实例化后，再添加一行如下的代码：

form1.setAlwaysOnTop(true);// 总是允许窗口置顶

2)时分秒更简单了，除一除转转换就行了，没有技术含量。

3)快捷键通过JButton类的setMnemonic方法实现

So,综上，整个程序的实现算法如下：

package hky.example;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.io.*;
import java.util.*;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.plaf.OptionPaneUI;


public class Demo{
    static boolean isRuning=false;
    static boolean isFirst=true;
    static Integer hmsCounter=0;
    static int hour,minute,second;
    
    @SuppressWarnings("unchecked")
    public static void main(String[] args) throws Exception {
 
        JFrame form1 = new JFrame("Form1");
        form1.setAlwaysOnTop(true);// 1)总是允许窗口置顶
        
        JTextField jTextField = new JTextField(10);
        jTextField.setSize(10, 10);
        jTextField.setText("0");
        jTextField.setEditable(false);
 
        JButton jButton = new JButton("开始");
        jButton.setSize(10, 10);
 
        
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                while (true) {
                    while(isRuning){
                    	++hmsCounter; 
                    	//3)时分秒显示
                    	hour=hmsCounter/3600;
                    	minute=hmsCounter%3600/60;
                    	second=hmsCounter%60;
                        jTextField.setText(hour+"时"+minute+"分"+second+"秒");
                        try {Thread.sleep(1000);} catch (Exception e2) {}
                    }
                    try {Thread.sleep(200);} catch (Exception e2) {}// 修复上一次回答的版本可能会存在的Bug
                }
            }
        });

        jButton.setMnemonic(KeyEvent.VK_ENTER);// 2)给JButton发送 Alt+Enter快捷键
        jButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
               String text=jButton.getText().equals("开始")?"暂停":"开始";
               jButton.setText(text);
               isRuning=!isRuning;
               if(isFirst){
                   thread.start();
                   isFirst=false;
               }
            }
        });
 
        JPanel panel = new JPanel();
        panel.setSize(200, 200);
        panel.add(jTextField, BorderLayout.NORTH);
        panel.add(jButton, BorderLayout.CENTER);
        form1.add(panel);
        form1.setBounds(200, 100, 250, 150);
        form1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        form1.addWindowListener(new WindowListener() {
            @Override
            public void windowOpened(WindowEvent e) {
                // TODO Auto-generated method stub
                 
            }
             
            @Override
            public void windowIconified(WindowEvent e) {
                // TODO Auto-generated method stub
                 
            }
             
            @Override
            public void windowDeiconified(WindowEvent e) {
                // TODO Auto-generated method stub
                 
            }
             
            @Override
            public void windowDeactivated(WindowEvent e) {
                // TODO Auto-generated method stub
                 
            }
             
            @Override
            public void windowClosing(WindowEvent e) {
               // 窗口关闭前取出文本框的数字保存到外部文件，代码在此处写
                JOptionPane.showMessageDialog(null, "Are you sure closing?");
            }
             
            @Override
            public void windowClosed(WindowEvent e) {
                // TODO Auto-generated method stub
                 
            }
             
            @Override
            public void windowActivated(WindowEvent e) {
                // TODO Auto-generated method stub
                 
            }
        });
        
        form1.setVisible(true);
    }
}

Answer 2

这个需求值得商榷。不是一时就能给你做出来的。