java - JFrame 中的 KeyEvent 由于可运行而无法工作

Question

我是java新手，所以我真的希望问题确实是由可运行程序引起的，它堵塞了关键事件监听器，就像我想的那样。我有类 Roll 调用另一个类 TimerImageSwapper，它在构建器中创建一个可运行的对象。稍后，Roll 通过类 main() 方法调用 TimerImageSwapper#run()。

TimerImageSwapper 的目的是通过显示随机面并落在某个值上来模拟立方体滚动。该方法的 main 在调用时接收调用者 JFrame 类作为输入，以便将结果显示在初始 JFrame 中。

一旦确定了数字，我希望用户能够通过按空格键使屏幕变暗。那是不起作用的部分。

附注我假设这是一个线程问题，因为它在 Debug模式下运行得很好。

滚动类如下所示:

package nofis;

import java.awt.Color;
import java.awt.Component;
import java.awt.event.KeyEvent;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Date;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;


public class Roll extends javax.swing.JFrame {

    private final long id;
    private final String filename;
    private int clicks = 0;

    public Roll(long id) {
        this.setUndecorated(true);
        this.setExtendedState(Roll.MAXIMIZED_BOTH);
        this.filename = "c:\\results\\test.csv";
        initComponents();
        this.id = id;
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jButton1 = new javax.swing.JButton();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setBackground(new java.awt.Color(204, 204, 255));
        addKeyListener(new java.awt.event.KeyAdapter() {
            public void keyPressed(java.awt.event.KeyEvent evt) {
                formKeyPressed(evt);
            }
        });

        jButton1.setText("text!");
        jButton1.addKeyListener(new java.awt.event.KeyAdapter() {
            public void keyPressed(java.awt.event.KeyEvent evt) {
                jButton1KeyPressed(evt);
            }
            public void keyReleased(java.awt.event.KeyEvent evt) {
                jButton1KeyReleased(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addGap(162, 162, 162)
                        .addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 429, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(399, 399, 399)
                        .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 101, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(layout.createSequentialGroup()
                        .addGap(271, 271, 271)
                        .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 221, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addGap(93, 93, 93)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 89, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 97, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(52, 52, 52))
        );

        pack();
    }// </editor-fold>                        

    private void formKeyPressed(java.awt.event.KeyEvent evt) {                                
        if (evt.getKeyCode() == KeyEvent.VK_SPACE) {
            if (clicks == 0) {
                clicks++;
                try {
                    rollDice();
                } catch (IOException ex) {
                    Logger.getLogger(Roll.class.getName()).log(Level.SEVERE, null, ex);
                }
            } else {
                while (!is.done) {
                    try {
                        this.wait(100);
                    } catch (InterruptedException ex) {
                        Logger.getLogger(Roll.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }

                for (Component c : this.getRootPane().getComponents()) {
                    c.setVisible(false);
                }

                this.setBackground(Color.black);
                revalidate();
//
                repaint();

            }
        }    }                               

    private void jButton1KeyReleased(java.awt.event.KeyEvent evt) {                                     
        // TODO add your handling code here:
    }                                    

    private void jButton1KeyPressed(java.awt.event.KeyEvent evt) {                                    
        if (evt.getKeyCode() == KeyEvent.VK_SPACE) {
            try {
                if (clicks == 0) {
                    clicks++;
                    try {
                        rollDice();
                    } catch (IOException ex) {
                        Logger.getLogger(Roll.class.getName()).log(Level.SEVERE, null, ex);
                    }
                    return;
                } else {
                    while (!is.done) {
                        this.wait(100);
                    }

//here i am going through all form elemets and make them disappear. 
                for (Component c : this.getRootPane().getComponents()) {
                    c.setVisible(false);
                }
                this.setBackground(Color.black);
                revalidate();
                repaint();
                }
            } catch (InterruptedException ex) {
                Logger.getLogger(Roll.class.getName()).log(Level.SEVERE, null, ex);
            }


        }    }                                   

    private void rollDice() throws IOException {
        jButton1.setVisible(false);
        is = new TimerImageSwapper(jLabel1, jLabel2);
        Random rand = new Random();
        int res = 1 + rand.nextInt(6);
        is.main(this, res);

        revalidate();
        repaint();

        {

        }
    }

    private static void updateCsvFile(String sFileName, Long id, Integer result, Date time) throws IOException {

        try (FileWriter writer = new FileWriter(sFileName, true)) {
            writer.append(id.toString());
            writer.append(',');
            writer.append(result.toString());
            writer.append(',');
            writer.append(time.toString());
            writer.append('\n');
            writer.flush();
        } catch (Exception e) {
        }

    }

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;

                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Roll.class
                    .getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Roll.class
                    .getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Roll.class
                    .getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Roll.class
                    .getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
    }
    private javax.swing.JLabel jlabel1;
    TimerImageSwapper is;
    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    // End of variables declaration                   

}

TimerImageSwaper 看起来像这样:

package nofis;

import java.awt.Component;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.swing.*;

public class TimerImageSwapper {

    public static final String[] IMAGES = {
        "dice1.png",
        "dice2.png",
        "dice3.png",
        "dice4.png",
        "dice5.png",
        "dice6.png"
    };

    private static final int TIMER_DELAY = 100;

    private ImageIcon[] icons = new ImageIcon[IMAGES.length];
    private final JLabel mainLabel;// = new JLabel();

    private int iconIndex = 0;
    private int max = 30;
    private int count = 0;
    public int res = 1;
    Timer timer = null;
    JLabel result =null;
    public boolean done = false;
    public TimerImageSwapper(JLabel mainLabel,JLabel jLabel2) throws IOException {
        for (int i = 0; i < icons.length; i++) {
            BufferedImage image = ImageIO.read(new File(IMAGES[i]));
            icons[i] = new ImageIcon(image);
        }
        this.mainLabel = mainLabel;
        this.result=jLabel2;


        mainLabel.setIcon(icons[iconIndex]);

        timer = new Timer(TIMER_DELAY, new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                Random rand = new Random();
                if (count >= max) {
                    timer.stop();
                    done=true;

                    res = iconIndex;
                    mainLabel.setIcon(icons[res-1]);
                    result.setFont(new java.awt.Font("Arial", Font.BOLD, 20));
                    result.setText("text: " + Integer.toString(res));

                    return;
                }
                count++;
                iconIndex=rand.nextInt(6)+1;
                mainLabel.setIcon(icons[iconIndex-1]);
            }
        });
        timer.start();
    }


    public Component getMainComponent() {
        return mainLabel;
    }

    private void createAndShowGui() {
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(this.getMainComponent());
        frame.setVisible(true);

    }
    JFrame frame;

    public void main(JFrame frame, int result) {
        this.frame = frame;
        res=result;

        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {

                createAndShowGui();
            }
        });
    }
}

我知道我有很多执行错误的代码，并且希望得到任何提示。

谢谢。

Answer 1

• 作为一般规则，我们不鼓励使用 KeyListener 是有原因的，相反，我们建议使用 key bindings API
• 此外，如果用户用鼠标单击按钮，您不应该在按钮上使用 KeyListener ？相反，您应该使用 ActionListener。请参阅How to Use Buttons, Check Boxes, and Radio Buttons和 How to Write an Action Listener
• while (!is.done) { 将会给你带来问题，因为 Swing 是单线程的，所以你永远不应该做任何会阻塞事件调度线程的事情，这会阻止 UI已更新或响应新事件。看看Concurrency in Swing更多细节。对于你的情况，我会考虑使用 Observer Pattern ，您的 Timer 将触发一个通知，您的 Roll 类将响应该通知