單擊兩次按鈕之間的JAVA時間

Question

我有一些代碼顯示了兩個按鈕的GUI，目標是按下一個按鈕兩次以顯示兩次單擊之間花費的時間（以毫秒為單位）。

盡管我的問題是時間始終為0。有什么建議嗎？ 我還想實現一種方法來獲取按鈕a和按鈕b的單擊之間的時間。 有小費嗎？ 謝謝。

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

在按鈕的第一次單擊中設置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");
    }

這將為您提供第一次點擊和第二次點擊之間的區別

Answer 2

在您的代碼中：

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?
    }

}}

這樣，您將不會在隨后的鼠標單擊事件之間花費時間。 想法是將startTime聲明為類減速中的成員。 在執行操作時計算經過的時間，然后通過將startTime設置為endTime來更新它。

Answer 3

使用System.nanotime（）代替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); 


    }

}