如何使定时器倒计时与进度条一起？ [英] How to make Timer countdown along with progress bar?

问题描述

如何使进度条慢慢降低时间限制？

How can I make it so that the progress bar slowly goes down with the time limit?

class GamePanel extends JPanel implements MouseListener, ActionListener
{
    private JButton quit;
    private JButton q;
    private Font loadFont;

    public GamePanel()
    {
        setBackground(Color.blue); // sets background color
        this.setLayout(null);
        quit = new JButton("Quit");
        quit.addActionListener(this);
        quit.setBounds(550, 700, 100, 30);
        this.add(quit);

        q = new JButton("Questions");
        q.addActionListener(this);
        q.setBounds(100, 100, 120, 30);
        this.add(q);

        loadFont = new Font("Serif", Font.PLAIN, 30);
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        g.setColor(Color.black);
        g.fillRect(80, 100, 610, 560);
        g.setColor(Color.white);
        g.fillRect(90, 110, 110, 100);// 1st column
        g.fillRect(90, 220, 110, 100);//
        g.fillRect(90, 330, 110, 100);//
        g.fillRect(90, 440, 110, 100);//
        g.fillRect(90, 550, 110, 100);//
        g.fillRect(210, 110, 110, 100);// 2nd column
        g.fillRect(210, 220, 110, 100);//
        g.fillRect(210, 330, 110, 100);//
        g.fillRect(210, 440, 110, 100);//
        g.fillRect(210, 550, 110, 100);//
        g.fillRect(330, 110, 110, 100);// 3rd column
        g.fillRect(330, 220, 110, 100);//
        g.fillRect(330, 330, 110, 100);//
        g.fillRect(330, 440, 110, 100);//
        g.fillRect(330, 550, 110, 100);//
        g.fillRect(450, 110, 110, 100);// 4th column
        g.fillRect(450, 220, 110, 100);//
        g.fillRect(450, 330, 110, 100);//
        g.fillRect(450, 440, 110, 100);//
        g.fillRect(450, 550, 110, 100);//
        g.fillRect(570, 110, 110, 100);// 5th column
        g.fillRect(570, 220, 110, 100);//
        g.fillRect(570, 330, 110, 100);//
        g.fillRect(570, 440, 110, 100);//
        g.fillRect(570, 550, 110, 100);//
        g.setColor(Color.green);
        g.setFont(loadFont);
        g.drawString(input + ":", 100, 710);
    }

    public void actionPerformed(ActionEvent e)
    {
        String order = e.getActionCommand();
        if(order.equals("Quit"))
            cards.show(c, "Introduction");
        if(order.equals("Questions"))
            cards.show(c, "Questions");
    }

    public void mousePressed(MouseEvent e) {}
    public void mouseReleased(MouseEvent e) {}
    public void mouseClicked(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
}

class QuestionPanel extends JPanel implements ActionListener
{
    private long startTime, elapsedTime;
    private Timer timer;
    private int countdown;
    private Font loadFont;

    public QuestionPanel()
    {
        setBackground(Color.pink); // sets background color
        this.setLayout(null);  // moved into constructor from ActionPerformed: only change layout in constructor
        startTime = 0;
        elapsedTime = 0;
        countdown = 590;
        loadFont = new Font("Segoe Script", Font.BOLD, 20);
        if(timer == null)
        {// use the biggest value possible that provides your desired time keeping precision (usually no less than 15 on Windows)
            timer = new Timer(100, this);  
            startTime = System.currentTimeMillis();  // gets start time in milliseconds
            timer.start();
        }
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        g.fillRect(100, 100, 600, 25);
        g.setColor(Color.green);
        g.fillRect(105, 105, countdown, 15);
        g.setColor(Color.black);
        g.setFont(loadFont);
        g.drawString("" + ((System.currentTimeMillis() - startTime) / 1000.0), 100, 80);  // display remaining time
    }

    public void actionPerformed(ActionEvent e)
    {
        String command = e.getActionCommand();
        elapsedTime = System.currentTimeMillis() - startTime;
        if(elapsedTime < (5000))
        {
            countdown--;
            repaint();
        }
        else
        {
            timer.stop();
            if(timer == null)
            {
                timer = new Timer(500, this);
                timer.start();
            }
        }
        if(elapsedTime >= (5000))  // can't use == here because of limited precision of system clock
            cards.show(c, "Correct!");
    }
}

class AnswerPanel extends JPanel implements ActionListener
{
    private JButton revert;

    public AnswerPanel()
    {
        setBackground(Color.yellow); // sets background color
        this.setLayout(null);
        revert = new JButton("Back");
        revert.addActionListener(this);
        revert.setBounds(340, 700, 100, 30);
        this.add(revert);
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
    }

    public void actionPerformed(ActionEvent e)
    {
        String directive = e.getActionCommand();
        if(directive.equals("Back"))
            cards.show(c, "Start");
    }
}

class FailPanel extends JPanel implements ActionListener
{
    private JButton turnaround;

    public FailPanel()
    {
        setBackground(Color.green); // sets background color
        this.setLayout(null);
        turnaround = new JButton("Back");
        turnaround.addActionListener(this);
        turnaround.setBounds(340, 700, 100, 30);
        this.add(turnaround);
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
    }

    public void actionPerformed(ActionEvent e)
    {
        String bidding = e.getActionCommand();
        if(bidding.equals("Back"))
            cards.show(c, "Start");
    }
}
}// end of the entire program

推荐答案

抱歉，我仍然找不到实际阅读代码的动机，但只是根据问题汇总了这个例子。看看它是否给你一些想法。

Sorry, I still could not find the motivation to actually read your code, but just threw together this example based on the question. See if it gives you some ideas.

请注意，它是一个SSCCE，总共只使用40行代码。

Note that it is an SSCCE and uses just 40 lines of code in all.

import java.awt.event.*;
import javax.swing.*;

class CountDownProgressBar {

    Timer timer;
    JProgressBar progressBar;

    CountDownProgressBar() {
        progressBar = new JProgressBar(JProgressBar.VERTICAL, 0, 10);
        progressBar.setValue(10);
        ActionListener listener = new ActionListener() {
            int counter = 10;
            public void actionPerformed(ActionEvent ae) {
                counter--;
                progressBar.setValue(counter);
                if (counter<1) {
                    JOptionPane.showMessageDialog(null, "Kaboom!");
                    timer.stop();
                } 
            }
        };
        timer = new Timer(1000, listener);
        timer.start();
        JOptionPane.showMessageDialog(null, progressBar);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater( new Runnable() {
            public void run() {
                CountDownProgressBar cdpb = new CountDownProgressBar();
            }
        });
    }
}

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