Question

我有一些代码显示两个按钮的GUI，目标是按两次按钮，显示按钮点击之间的毫秒数。

虽然我的问题是时间总是0.有什么建议吗？我还想实现一种方法来获得按钮a和按钮b的点击之间的时间。有小费吗？感谢。

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

public class ButtonViewer 
{
    static int countA = 0;
    static int countB = 0;
public static void main( String[] args ) 
{
JFrame frame = new JFrame();
GridLayout layout = new GridLayout(2,2);
frame.setLayout(layout);
JButton buttonA = new JButton("Button A");
frame.add(buttonA);

class ClickListenerOne implements ActionListener 
{
    public void actionPerformed( ActionEvent event ) 
    {
        countA++;
        long StartA = System.currentTimeMillis();

        if (countA % 2 == 0)
        {
             long EndA = System.currentTimeMillis();
             long differenceA = (EndA - StartA);
             System.out.println(differenceA + " Elapsed");  
        }

    }
}

JButton buttonB = new JButton("Button B");
frame.add(buttonB);

class ClickListenerTwo implements ActionListener 
{
    public void actionPerformed( ActionEvent event ) 
    {
        countB++;
        long StartB = System.currentTimeMillis();
        if (countB % 2 == 0)
        {
             long EndB = System.currentTimeMillis();
             long differenceB = (EndB - StartB);
             System.out.println(differenceB + " Elapsed");  
        }
    }
}

ActionListener mButtonAClicked = new ClickListenerOne();
buttonA.addActionListener(mButtonAClicked);

ActionListener mButtonBClicked = new ClickListenerTwo();
buttonB.addActionListener(mButtonBClicked);

frame.setSize( 200, 200 );
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.setVisible(true);
}
}

Answer 1

在按钮的第一次点击中设置StartA，即

 long StartA;
public void actionPerformed( ActionEvent event )
{
    countA++;
    if (countA % 2 != 0)
  StartA = System.currentTimeMillis();

    if (countA % 2 == 0)
    {
         long EndA = System.currentTimeMillis();
         long differenceA = (EndA - StartA);
         System.out.println(differenceA + " Elapsed");
    }

这将为您提供第一次点击和第二次点击之间的区别

Answer 2

在您的代码中：

class ClickListenerOne implements ActionListener {
 // int startA; ?
public void actionPerformed( ActionEvent event ) 
{
    countA++;
    long StartA = System.currentTimeMillis();  // you are reading  time 
                              //after mouse click event

    if (countA % 2 == 0)
    {
         long EndA = System.currentTimeMillis(); // variable name should not be 
                              //declared with capital letter
         long differenceA = (EndA - StartA);
         System.out.println(differenceA + " Elapsed");// then you are computing 
                                 //elapsed time in the same click event 
         // startA = endA; // updated the time after each event?
    }

}}

这样，您在后续鼠标单击事件之间就不会有经过的时间。我们的想法是将startTime声明为班级减速中的成员。计算经过的时间，然后通过将其设置为startTime来更新endTime。

Answer 3

使用System.nanotime（）而不是System.currentTimeMillis（）

public void actionPerformed( ActionEvent event ) 
{
    countA++;
    if(countA % 2 != 0){
    StartA = System.nanoTime();
    }

    if (countA % 2 == 0)
    {
         EndA = System.nanoTime();
         differenceA = EndA- StartA;
         System.out.println(differenceA); 


    }

}

按钮点击之间的JAVA时间

3 个答案: