Java倒计时计时器重置问题

我用java编写了一个倒计时程序。它从用户在组合框中选择的任何数字开始倒计时，共有3个数字（小时、分钟、秒）。这个部件工作得很好

当我按下“重置”按钮时，问题就出现了。它清除我用来显示剩余时间的标签，并使它们显示“00”。但当我再次按下“开始”时，它会以剩下的秒数回忆起上次的位置，并从那里开始

请帮忙

以下是我的计时器代码：

private void JButtonActionPerformed(java.awt.event.ActionEvent evt) {                                        

    timer = new Timer(1000, new ActionListener(){


        @Override
        public void actionPerformed(ActionEvent e){

        onoff = true; 


        if(hours == 1 && min == 0 && sec ==0){

            repaint();
            hours--;
            lblHours.setText("00");
            min=59;
            sec=60;

        }

         if(sec == 0 && min <= 59 && min>0){   

             sec=60;
             min--;
             lblHours.setText("00");

         }

         if(sec == 0 && hours == 0 && min<=0){

             repaint();
             JOptionPane.showMessageDialog(rootPane, "You have run out of time and did not manage to escape!", "Time is up!!", 0 );
             hours = 0; min = 0; sec = 0;
             timer.stop();
         }

         else{

             sec--;
             repaint();

             if (sec<10){

             lblSeconds.setText("0"+sec);
             repaint();
             flag = false;

             }
             if (hours==0){

                 repaint();
                 lblHours.setText("00");

             if (min<10)

                 repaint();
                 lblMinutes.setText("0"+min);

                 if (sec<10)

                     lblSeconds.setText("0"+sec);

                 else

                     lblSeconds.setText(""+sec);


             }
             if(flag){
             lblHours.setText(""+hours);
             lblMinutes.setText(""+min);
             lblSeconds.setText(""+sec);
             repaint();

             }


         }
    }

});

    timer.start();


} 

我知道我对重新油漆有点疯狂；但是我不知道我打算多久用一次，哈哈

---

任何帮助/指导都将不胜感激。

不，在您可用的任何地方，断章取义，代码您是否重置变量<代码>小时，<代码>分钟，<代码>秒

这可以通过简单地在您的数据和一些简单的州周围放入一些打印语句来解决

话虽如此，这是一种幼稚的做法

Swing

计时器（甚至
线程。睡眠
）只能保证“至少”持续时间

好的，所以你不是在开发一个超高分辨率的计时器，但是你仍然需要理解这会导致“漂移”，特别是在一个很长的时间内

“更好”的解决方案是计算计时器启动后经过的时间。幸运的是，Java现在以更新的日期/时间API的形式提供了大量支持

下面的示例使用了一个简单的“秒表”概念，即自启动以来经过的时间量。它本身并没有实际的滴答声，这使得它非常有效

但是向前移动的时钟将如何帮助你呢？实际上很多。您可以计算剩余时间，但从当前经过的时间量（自启动以来）中减去所需的运行时间，然后进行倒计时。简单

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 java.time.Duration;
import java.time.Instant;
import java.time.temporal.ChronoUnit;
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 class StopWatch {

    private Instant startTime;
    private Duration totalRunTime = Duration.ZERO;

    public void start() {
      startTime = Instant.now();
    }

    public void stop() {
      Duration runTime = Duration.between(startTime, Instant.now());
      totalRunTime = totalRunTime.plus(runTime);
      startTime = null;
    }

    public void pause() {
      stop();
    }

    public void resume() {
      start();
    }

    public void reset() {
      stop();
      totalRunTime = Duration.ZERO;
    }

    public boolean isRunning() {
      return startTime != null;
    }

    public Duration getDuration() {
      Duration currentDuration = Duration.ZERO;
      currentDuration = currentDuration.plus(totalRunTime);
      if (isRunning()) {
        Duration runTime = Duration.between(startTime, Instant.now());
        currentDuration = currentDuration.plus(runTime);
      }
      return currentDuration;
    }
  }

  public static void main(String[] args) throws InterruptedException {
    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 class TestPane extends JPanel {

    private JLabel label;
    private JButton btn;

    private StopWatch stopWatch = new StopWatch();
    private Timer timer;

    public TestPane() {
      label = new JLabel("...");
      btn = new JButton("Start");

      setLayout(new GridBagLayout());
      GridBagConstraints gbc = new GridBagConstraints();
      gbc.gridwidth = GridBagConstraints.REMAINDER;

      add(label, gbc);
      add(btn, gbc);

      timer = new Timer(500, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
          Duration runningTime = Duration.of(10, ChronoUnit.MINUTES);
          Duration remainingTime = runningTime.minus(stopWatch.getDuration());
          System.out.println("RemainingTime = " + remainingTime);
          if (remainingTime.isZero() || remainingTime.isNegative()) {
            timer.stop();
            label.setText("0hrs 0mins 0secs");
          } else {
            long hours = remainingTime.toHours();
            long mins = remainingTime.toMinutesPart();
            long secs = remainingTime.toSecondsPart();
            label.setText(String.format("%dhrs %02dmins %02dsecs", hours, mins, secs));
          }
        }
      });
      timer.start();

      btn.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
          if (stopWatch.isRunning()) {
            stopWatch.pause();
            btn.setText("Start");
          } else {
            stopWatch.resume();
            btn.setText("Pause");
          }
        }
      });

    }

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

  }

}

你没有重置
小时
，
分钟
，
秒
你在哪里重置
小时
，
分钟
和
秒
？我只想指出，这是一种幼稚的方法。Swing
计时器（甚至
线程。睡眠
）只能保证“至少”持续时间。好吧，这不是一个超高分辨率的计时器，但你仍然需要了解，这可能会导致“漂移”，特别是在很长一段时间内。“更好”的解决方案是计算计时器启动后经过的时间。幸运的是，Java现在包含了很多对这方面的支持-
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 java.time.Duration;
import java.time.Instant;
import java.time.temporal.ChronoUnit;
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 class StopWatch {

    private Instant startTime;
    private Duration totalRunTime = Duration.ZERO;

    public void start() {
      startTime = Instant.now();
    }

    public void stop() {
      Duration runTime = Duration.between(startTime, Instant.now());
      totalRunTime = totalRunTime.plus(runTime);
      startTime = null;
    }

    public void pause() {
      stop();
    }

    public void resume() {
      start();
    }

    public void reset() {
      stop();
      totalRunTime = Duration.ZERO;
    }

    public boolean isRunning() {
      return startTime != null;
    }

    public Duration getDuration() {
      Duration currentDuration = Duration.ZERO;
      currentDuration = currentDuration.plus(totalRunTime);
      if (isRunning()) {
        Duration runTime = Duration.between(startTime, Instant.now());
        currentDuration = currentDuration.plus(runTime);
      }
      return currentDuration;
    }
  }

  public static void main(String[] args) throws InterruptedException {
    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 class TestPane extends JPanel {

    private JLabel label;
    private JButton btn;

    private StopWatch stopWatch = new StopWatch();
    private Timer timer;

    public TestPane() {
      label = new JLabel("...");
      btn = new JButton("Start");

      setLayout(new GridBagLayout());
      GridBagConstraints gbc = new GridBagConstraints();
      gbc.gridwidth = GridBagConstraints.REMAINDER;

      add(label, gbc);
      add(btn, gbc);

      timer = new Timer(500, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
          Duration runningTime = Duration.of(10, ChronoUnit.MINUTES);
          Duration remainingTime = runningTime.minus(stopWatch.getDuration());
          System.out.println("RemainingTime = " + remainingTime);
          if (remainingTime.isZero() || remainingTime.isNegative()) {
            timer.stop();
            label.setText("0hrs 0mins 0secs");
          } else {
            long hours = remainingTime.toHours();
            long mins = remainingTime.toMinutesPart();
            long secs = remainingTime.toSecondsPart();
            label.setText(String.format("%dhrs %02dmins %02dsecs", hours, mins, secs));
          }
        }
      });
      timer.start();

      btn.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
          if (stopWatch.isRunning()) {
            stopWatch.pause();
            btn.setText("Start");
          } else {
            stopWatch.resume();
            btn.setText("Pause");
          }
        }
      });

    }

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

  }

}