java - 按钮 Action 监听器

Question

好的，所以我编写了一个简单的程序，每次单击按钮时都会将值添加到计数器中。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，而是在循环完成时更新值。这是我的代码:

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，我是初学者...感谢所有帮助:)

Answer 1

查看有关如何使用的教程 Swing Timer然后看看我的解决方案:

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);
            }
        });
    }
}