我不知道如何在停止时显示计时器 [英] I don't know how to display timer when stopped

问题描述

你们都好吗？我的代码有点问题。当我停止我的计时器程序时，它会说完成！因为我把它设置为完成，但我想显示剩余时间而不是完成这个词。例如，如果我原始时间设置为4000秒并且我在3000秒停止，我想显示当前时间，即停止时的3000而不是单词完成。你们能帮助我吗？我真的很感激。

How are you all doing? I have a little problem with my code. When I stop my timer program, it will say "Done!" since I set it to "Done", but I would like to display the remaining time instead of the word "Done". Like for example if I the original time set is 4000 Seconds and I stopped at 3000 seconds I want to display the current time which is 3000 when stopping it instead of the word "Done". Can you guys help me out? I would really appreciate it.

这是我的代码：

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

import javax.swing.*;
public class CountdownTimer extends JFrame  {

    JLabel promptLabel, timerLabel;
    int counter;
    JLabel tf;
    JButton button;
    Timer timer;


    public static void main(String args[]) {

        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new CountdownTimer();
            }

        });

    }


    public CountdownTimer() {

        JFrame lt = new JFrame();
            lt.getContentPane().setBackground(new Color(0, 102, 153));
            lt.setBounds(100, 100, 450, 300);
            lt.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            lt.getContentPane().setLayout(null);
            lt.setVisible(true);

        promptLabel = new JLabel("Time: ", SwingConstants.CENTER);
        promptLabel.setFont(new Font("Modern No. 20", Font.BOLD, 17));
        promptLabel.setBounds(21, 30, 210, 30);
        lt.add(promptLabel);

        tf = new JLabel("4000");
        tf.setBounds(160, 36, 40, 20);
        lt.add(tf);

        button = new JButton("Start");
        button.setFont(new Font("Modern No. 20", Font.BOLD, 11));
        button.setBounds(299, 37, 89, 23);
        lt.add(button);

        JButton btnLogout = new JButton("LOGOUT");

        btnLogout.setBackground(new Color(112, 128, 144));
        btnLogout.setFont(new Font("Trajan Pro", Font.BOLD, 17));
        btnLogout.setBounds(149, 189, 121, 36);
        btnLogout.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                 String sbutt = e.getActionCommand();

                 if(sbutt.equals("LOGOUT")) {


                     long current = counter;
                     long elapsed = current - counter;

                        timer.stop();
                        timerLabel.setText("Done!");
                        Toolkit.getDefaultToolkit().beep();
                        tf.setText(String.valueOf(elapsed));

                 }
            }
        });
        lt.getContentPane().add(btnLogout);

        timerLabel = new JLabel("Waiting...", SwingConstants.CENTER);
        timerLabel.setFont(new Font("Modern No. 20", Font.BOLD, 17));
        timerLabel.setBounds(119, 97, 176, 62);
        lt.getContentPane().add(timerLabel);

        event e =  new event();
        button.addActionListener(e);
    }
    public void actionPerformed(ActionEvent e) {
        throw new UnsupportedOperationException("Not supported yet.");
    }
    public void run() {
        throw new UnsupportedOperationException("Not supported yet.");
    }
    public class event implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            int count = (int)(Double.parseDouble(tf.getText()));
            timerLabel.setText("Time left: " + count);
            TimeClass tc = new TimeClass(count);
            timer = new Timer(1000, tc);
            timer.start();
        }
    }
    public class TimeClass implements ActionListener {
        int counter;
        public TimeClass(int counter) {
            this.counter= counter;
   }
        public void actionPerformed(ActionEvent tc) {
            counter--;
            if(counter >= 1) {
                timerLabel.setText("Time left: " + counter);
            }
            else {
                timer.stop();
                timerLabel.setText("Done!");
                Toolkit.getDefaultToolkit().beep();
            }
        }
    }
}

推荐答案

但我希望显示剩余时间而不是单词Done。

but I would like to display the remaining time instead of the word "Done".

将 timerLabel.setText（Done！）; 改为 timerLabel.setText（counter）; ？

我应该指出，由于它的性质，Swing 计时器并不完全准确，你应该关注已经过去的时间量，而不是定时器被调用的频率。这当然完全取决于你想要计数的准确程度，但是值得知道（恕我直言）

I should point out that because of it's nature, Swing Timer is not entirely accurate and you should be focusing the amount of time that has passed and not how often the timer has been called. This of course comes entirely down to how accurate you want the count to be of course, but it's worth knowing (IMHO)

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public static class TestPane extends JPanel {

        private JLabel label;
        private JButton button;

        private Timer timer;
        private long startedAt;

        public static final int RUN_TIME = 5000;

        public TestPane() {
            label = new JLabel("...");
            button = new JButton("Start");
            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridwidth = GridBagConstraints.REMAINDER;

            add(label, gbc);
            add(button, gbc);

            button.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    if (timer == null) {
                        button.setText("Stop");
                        startedAt = System.currentTimeMillis();
                        timer = new Timer(500, new ActionListener() {
                            @Override
                            public void actionPerformed(ActionEvent e) {
                                long diff = System.currentTimeMillis() - startedAt;
                                if (diff >= RUN_TIME) {
                                    label.setText("Out of time; Used: " + remainingTime() + "s; remaining " + usedTime() + "s");
                                    timer.stop();
                                    button.setText("Start");
                                } else {
                                    label.setText("Used: " + remainingTime() + "s; remaining " + usedTime() + "s");
                                }
                            }
                        });
                        label.setText("Used: " + remainingTime() + "s; remaining " + usedTime() + "s");
                        timer.start();
                    } else {
                        timer.stop();
                        long diff = System.currentTimeMillis() - startedAt;
                        label.setText("Used: " + remainingTime() + "s; remaining " + usedTime() + "s");
                        button.setText("Start");
                        timer = null;
                    }
                }
            });
        }

        public int remainingTime() {
            long diff = System.currentTimeMillis() - startedAt;
            return (int) Math.round((RUN_TIME - diff) / 1000d);
        }

        public int usedTime() {
            long diff = System.currentTimeMillis() - startedAt;
            return (int) Math.round(diff / 1000d);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(300, 200);
        }

    }

}

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