Question

我正在研究Java中的节拍器实现。我已经读过使用Thread.sleep并不是实际同步时间的最好方法，这可能是我问题的根源。但是，我在实现的开始阶段遇到的问题是，当我使用+/-按钮时，bpm会发生变化，但是文本的速度会变化，并且＃34; RUNNING＆＃34;当你只从60转到61转时，会急剧增加。

为什么会出现这种情况的任何帮助都会很棒。我也有兴趣将thread.sleep（）更改为不同的东西，但midi选项有点超出我的头脑，我找不到任何好的文档来帮助我使用该选项。

由于

到目前为止，这是我的代码：

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.concurrent.atomic.AtomicBoolean;

public class mainWindow
{
    public static void main (String[] args){
        frameClass frame = new frameClass();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(350,275);
        frame.setVisible(true);
   }
}

class frameClass extends JFrame
{
    private JButton onOff;
    private JButton plus;
    private JButton minus;

    public frameClass()
    {
      setLayout(new FlowLayout());
      onOff = new JButton("On/Off");
     plus = new JButton("+");
     minus = new JButton("-");
     add(onOff);
     add(plus);
     add(minus);

     toggleHandler handler = new toggleHandler();
     onOff.addActionListener(handler);

     plusHandler plusHandle = new plusHandler();
     plus.addActionListener(plusHandle);

    minusHandler minusHandle = new minusHandler();
    minus.addActionListener(minusHandle);
}

private class toggleHandler implements ActionListener {
    private Metronome metro;

    @Override
    public void actionPerformed(java.awt.event.ActionEvent e) {
        if (e.getSource() == onOff) {
            if (metro == null) {
                metro = new Metronome();
                Thread t = new Thread(metro);
                t.start();
            } else {
                metro.end();
                metro = null;
            }
        }
    }

}

private class plusHandler implements ActionListener
{
    @Override
    public void actionPerformed(java.awt.event.ActionEvent e)
    {
        Metronome.bpm++;
    }
}

private class minusHandler implements ActionListener
{
    @Override
    public void actionPerformed(java.awt.event.ActionEvent e)
    {
        Metronome.bpm--;
    }
}
 }

class Metronome extends Thread
{
private AtomicBoolean keepRunning;
static double bpm = 60;

public Metronome()
{
    keepRunning = new AtomicBoolean(true);
}

public void end()
{
    keepRunning.set(false);
    System.out.println("STOPPED");
}

@Override
public void run()
{
    while (keepRunning.get())
    {
        try
        {
            Thread.sleep((long)(1000*(60.0/bpm)));
        }
        catch(InterruptedException e)
        {
            e.printStackTrace();
        }

        System.out.println("RUNNING");
    }
}
}

Answer 1

问题出在这一行：

Thread.sleep((long)(1000*(60/bpm)));

当bpm变为61时，超时变为0.这是因为整数除60/61 = 0。

尝试改为：

Thread.sleep((long)(1000*(60.0/bpm)));

Java中的节拍器

1 个答案: