按钮ActionListener [英] Button ActionListener

问题描述

好，所以我制作了一个简单的程序，每次单击按钮时都会添加该值以进行计数. 现在，我想添加自动"按钮功能，以在单击自动"按钮时增加计数器的值.我遇到了问题，因为它不会在屏幕上呈现每个计数器值，而是在循环完成后更新值.这是我的代码:

Ok, so I made a simple program that adds the value to counter each time a button is clicked. Now, I would like to add "Auto" button feature to increase the value of the counter when the "Auto" button is clicked. I'm having problems with it because it won't render each counter value on the screen, instead the value updates when the loop is done.. Here is my code:

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.concurrent.TimeUnit;
import javax.swing.JButton;
import javax.swing.JFrame;


public class Gui extends JFrame{

    private static final long serialVersionUID = 1L;

    private JButton uselesButton;

    private JButton autoButton;

    private FlowLayout layout;
    private long counter = 0;

    public Gui() {
        super("Button");
        layout = new FlowLayout(FlowLayout.CENTER);
        this.setLayout(layout);

        uselesButton = new JButton(String.format("Pressed %d times", counter));
        add(uselesButton);
        uselesButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                counter++;
                uselesButton.setText(String.format("Pressed %d times", counter));
            }

        });

        autoButton = new JButton("Auto");
        add(autoButton);
        autoButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                        for(long i =0; i < 99999999;i++) {
                        try {
                            TimeUnit.MILLISECONDS.sleep(10);
                        } catch (InterruptedException e1) {
                            System.out.println("ERROR");
                        }
                        counter = i;
                        uselesButton.setText(String.format("Pressed %d times", counter));
                    }
                    }
        });
    }
}

请记住，我是一个初学者...感谢所有帮助:)

Keep in mind that I'm a beginner... All help appreciated :)

推荐答案

看看有关如何使用

Take a look at the tutorial about How to Use Swing Timer and then look at my solution:

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

public class Gui extends JFrame {

    private static final long serialVersionUID = 1L;
    private JButton uselesButton;
    private JButton autoButton;
    private FlowLayout layout;
    private long counter = 0;
    private javax.swing.Timer timer;

    public Gui() {
        super("Button");
        layout = new FlowLayout(FlowLayout.CENTER);
        setLayout(layout);
        setDefaultCloseOperation(3);
        setSize(300, 300);
        setLocationRelativeTo(null);

        //initialing swing timer
        timer = new javax.swing.Timer(100, getButtonAction());

        autoButton = new JButton("Auto");
        add(autoButton);
        autoButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                if (!timer.isRunning()) {
                    timer.start();
                } else {
                    timer.stop();
                }
            }
        });
    }

    private ActionListener getButtonAction() {
        ActionListener action = new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                autoButton.setText(String.format("Pressed %d times", ++counter));
                if (counter > 1000) {
                    timer.stop();
                }
            }
        };
        return action;
    }

    public static void main(String... args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Gui().setVisible(true);
            }
        });
    }
}

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