Start timer (javax.swing) on button-click rather than on its own

I have added a button, that is initially "Please Wait" and changes to "Click Here" as the timer starts. I need to make it so that if the button is clicked, whilst the text is "Please Wait", it starts the timer, rather than having the timer start itself after the 3000ms.

I also am wondering how I could make the restart button, actually restart the test.

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JButton;
import java.awt.FlowLayout;
import java.awt.GridBagLayout;
import java.awt.Dimension;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.Timer;
public class Main extends JFrame implements ActionListener
{
private static final long serialVersionUID = 1L;
//Width and Height of the JFrame
public static final int WIDTH = 550;
public static final int HEIGHT = 550;
//Width and Height of the Add Button
public static final int WIDTH1 = 450;
public static final int HEIGHT1 = 450;
//Width and Height of Restart Button
public static final int WIDTH2 = 125;
public static final int HEIGHT2 = 25;
//Adding the 3 main components
//This is the label that counts the clicks
private JLabel lblValue;
//This is the integer that counts the clicks
private int clicks = 0;
//This is the timer
private int count = 6;
public static void main(String[] args)
{
// This creates two instances of Main,
// which creates two different windows.
Main counter1 = new Main( );
counter1.setVisible(true);
Main counter2 = new Main( );
counter2.setVisible(true);
}
public Main( )
{
//Title that appears at the top of the page
setTitle("CPS Test");
//Close when the close button is pressed
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Setting size of the frame
setSize(WIDTH, HEIGHT);
setMaximumSize(new Dimension(WIDTH, HEIGHT));
setMinimumSize(new Dimension(WIDTH, HEIGHT));
setLayout(new FlowLayout( ));
// This is the label for the amount of clicks
lblValue = new JLabel("0");
//Adding the counter onto the screen
add(lblValue);
//This is the button that adds 1 every time clicked
JButton addButton = new JButton("Please Wait");
addButton.addActionListener(this);
//Setting size for button
addButton.setSize(new Dimension(WIDTH1, HEIGHT1));
addButton.setPreferredSize(new Dimension(WIDTH1, HEIGHT1));
addButton.setMinimumSize(new Dimension(WIDTH1, HEIGHT1));
addButton.setMaximumSize(new Dimension(WIDTH1, HEIGHT1));
//Adding button onto screen
add(addButton);
JButton resetButton = new JButton("Restart");
//Setting size for button
resetButton.setSize(new Dimension(WIDTH2, HEIGHT2));
resetButton.setPreferredSize(new Dimension(WIDTH2, HEIGHT2));
resetButton.setMinimumSize(new Dimension(WIDTH2, HEIGHT2));
resetButton.setMaximumSize(new Dimension(WIDTH2, HEIGHT2));
//Adds the label for the timer. This changes after 1000 milliseconds to 1, and then counts every second
JLabel label = new JLabel("Starting Soon");
setLayout(new GridBagLayout());
//Adding timer onto the screen
add(label);
//Delay in milliseconds between number adding
Timer timer = new Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent e) {
//Add 1 to count every interval of 1000 milliseconds
count--;
//Timer keeps ticking till this number is achieved
if (count >= 0) {
label.setText(Integer.toString(count));
}
//Will stop timer, remove the click button and will calculate how many clicks you got per second
else {
((Timer) (e.getSource())).stop();
remove(addButton);
label.setText("");
lblValue.setText("You clicked " + clicks / 5d + " clicks per second.");
add(resetButton);
}
//Will change text from "Please Wait" to "Click Here" after timer delay has finished
if (count == 5) {
addButton.setText("Click Here");
}
}
});
//Timer wont start for 3000 milliseconds
timer.setInitialDelay(3000);
//Start Timer
timer.start();
}
public void actionPerformed(ActionEvent e)
{
String actionCommand = e.getActionCommand( );
//This will only work whilst the text is "Click Here". Wont work for 1000 milliseconds as the text is "Please Wait"
if (actionCommand.equals("Click Here"))
{
//Adds 1 to the click counter ever time it is clicked
lblValue.setText(Integer.toString(clicks += 1));
}
}
}```
</details>
# 答案1
**得分**: 4
根据[Andrew Thompson][1]的指示，你需要完成四个步骤来解决这个问题。
**1.) 计时器应该是类的全局变量**
这一步很重要，否则对象无法从我们即将创建的ActionListeners内部访问。
```java
import javax.swing.Timer;
public class Test {
private Timer timer;
public Test() {
}
}

2.) 在构造函数中创建计时器元素

在构造函数中，我们将初始化计时器，但是重要的是 - 我们暂时不会启动它。

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;

public class Test {
  private Timer timer;
  private int count = 0;
  
  public Test() {
    ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        //计时器应该做什么？
        count++;
        System.out.println(count);
      }
    }; 
    timer = new Timer(1000, taskPerformer);
  }
}

3.) 在开始按钮的ActionListener中启动计时器

在这一步中，我们通过按下按钮来启动计时器的功能。为此，我们使用了一个ActionListener和计时器的start()方法。

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.Timer;

public class Test {
  private Timer timer;
  private int count = 0;
  
  public Test() {
    ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        //计时器应该做什么？
        count++;
        System.out.println(count);
      }
    }; 
    timer = new Timer(1000, taskPerformer);
    
    JButton start = new JButton("开始");
    
    //在这里添加功能
    start.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(!timer.isRunning()) {
          System.out.println("计时器已启动！");
          timer.start();
        } 
      }
    }); 
  }
}

4.) 在停止按钮的ActionListener中停止计时器

这基本上是相反的过程。我们将创建另一个按钮，以添加停止计时器功能。为此，我们再次使用ActionListener和计时器的stop()方法。

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.Timer;

public class Test {
  private Timer timer;
  private int count = 0;
  
  public Test() {
    ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        //计时器应该做什么？
        count++;
        System.out.println(count);
      }
    }; 
    timer = new Timer(1000, taskPerformer);
    
    JButton start = new JButton("开始");
    start.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(!timer.isRunning()) {
          System.out.println("计时器已启动！");
          timer.start();
        } 
      }
    });
    
    //在这里添加功能
    JButton stop = new JButton("停止");
    stop.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(timer.isRunning()) {
          count = 0;
          System.out.println("计时器已停止！");
          timer.stop();
        } 
      }
    });
  }
}

最后一步：创建其余的GUI

这对于回答你的问题不再必要，但我想提供一个最小的工作示例。为此，我使用了SwingUtilities.invokeLater()。关于这是在做什么以及为什么应该使用它的更多信息，请参阅这个问题。

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;

public class Test {
  private Timer timer;
  private int count = 0;
  
  public Test() {
    ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        //计时器应该做什么？
        count++;
        System.out.println(count);
      }
    }; 
    timer = new Timer(1000, taskPerformer);
    
    JButton start = new JButton("开始");
    start.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(!timer.isRunning()) {
          System.out.println("计时器已启动！");
          timer.start();
        } 
      }
    });
    
    JButton stop = new JButton("停止");
    stop.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(timer.isRunning()) {
          count = 0;
          System.out.println("计时器已停止！");
          timer.stop();
        } 
      }
    });
    
    //最小工作示例
    JFrame frame = new JFrame("计时器");
    JPanel panel = new JPanel();
    panel.setLayout(new FlowLayout());

    panel.add(start);
    panel.add(stop);
    frame.add(panel);
    
    frame.setSize(300,300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }
  
  public static void main(String[] args) {
    SwingUtilities.invokeLater(Test::new);
  }
}

import javax.swing.Timer;

public class Test {
  private Timer timer;
  
  public Test() {

  }
}

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;

public class Test {
  private Timer timer;
  private int count = 0;
  
  public Test() {
    ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        //What should the timer do?
        count++;
        System.out.println(count);
      }
    }; 
    timer = new Timer(1000, taskPerformer);
  }
}

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.Timer;

public class Test {
  private Timer timer;
  private int count = 0;
  
  public Test() {
    ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        //What should the timer do?
        count++;
        System.out.println(count);
      }
    }; 
    timer = new Timer(1000, taskPerformer);
    
    JButton start = new JButton("Start");
    
    //Here the functionality is added
    start.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(!timer.isRunning()) {
          System.out.println("Timer started!");
          timer.start();
        } 
      }
    }); 
  }
}

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.Timer;

public class Test {
  private Timer timer;
  private int count = 0;
  
  public Test() {
    ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        //What should the timer do?
        count++;
        System.out.println(count);
      }
    }; 
    timer = new Timer(1000, taskPerformer);
    
    JButton start = new JButton("Start");
    start.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(!timer.isRunning()) {
          System.out.println("Timer started!");
          timer.start();
        } 
      }
    });
    
    //Functionality is added here
    JButton stop = new JButton("stop");
    stop.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(timer.isRunning()) {
          count = 0;
          System.out.println("Timer stopped!");
          timer.stop();
        } 
      }
    });
  }
}

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;

public class Test {
  private Timer timer;
  private int count = 0;
  
  public Test() {
    ActionListener taskPerformer = new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        //What should the timer do?
        count++;
        System.out.println(count);
      }
    }; 
    timer = new Timer(1000, taskPerformer);
    
    JButton start = new JButton("Start");
    start.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(!timer.isRunning()) {
          System.out.println("Timer started!");
          timer.start();
        } 
      }
    });
    
    JButton stop = new JButton("stop");
    stop.addActionListener(new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent arg0) {
        if(timer.isRunning()) {
          count = 0;
          System.out.println("Timer stopped!");
          timer.stop();
        } 
      }
    });
    
    //Minimal working example 
    JFrame frame = new JFrame("Timer");
    JPanel panel = new JPanel();
    panel.setLayout(new FlowLayout());

    panel.add(start);
    panel.add(stop);
    frame.add(panel);
    
    frame.setSize(300,300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }
  
  public static void main(String[] args) {
    SwingUtilities.invokeLater(Test::new);
  }
}