KeyListener 在带有 Netbeans 的 Java 中不起作用 [重复]

Question

我正在用netbeans中的Java编写一个Enigma Machine模拟器，我想做的是当用户按下一个键时，键盘类上JLabel的相应图标变为另一个但事件KeyListener没有工作，我在很多网站中进行了调查，这是一个焦点问题，但我尝试了所有方法但仍然无法正常工作，我有三个类：KeyBoard(JPanel)、Machine(JPanel) 和 EnigmaMain(JFrame)，并且 keylistener 在键盘类。代码如下：

键盘：

import java.awt.event.KeyEvent;
import javax.swing.ImageIcon;
import javax.swing.JLabel;


public class Keyboard extends javax.swing.JPanel {

/**
 * Creates new form Keyboard
 */
public Keyboard() {
    initComponents();
}

/**
 * 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() {

    keyA = new javax.swing.JLabel();

    setMinimumSize(new java.awt.Dimension(688, 253));
    setOpaque(false);
    setPreferredSize(new java.awt.Dimension(688, 253));
    addKeyListener(new java.awt.event.KeyAdapter() {
        public void keyPressed(java.awt.event.KeyEvent evt) {
            formKeyPressed(evt);
        }
    });
    setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());

    keyA.setIcon(new javax.swing.ImageIcon(getClass().getResource("/resources/keys/keyAreleased.png"))); // NOI18N
    add(keyA, new org.netbeans.lib.awtextra.AbsoluteConstraints(80, 70, -1, -1));
}// </editor-fold>                        

private void formKeyPressed(java.awt.event.KeyEvent evt) {                                
    ImageIcon image = new ImageIcon(getClass().getResource("/resources/keys/keyApressed.png"));
    keyA.setIcon(image);
}                               

public JLabel getKeyA(){
    return this.keyA;
}

// Variables declaration - do not modify                     
private javax.swing.JLabel keyA;
// End of variables declaration                   
}

机器：

import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.ImageIcon;

public class Machine extends javax.swing.JPanel{

/**
 * Creates new form Machine
 */
public Machine() {
    initComponents();
}

/**
 * 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() {

    keyboard1 = new GUI.Keyboard();
    backgroundImage = new javax.swing.JLabel();

    setPreferredSize(new java.awt.Dimension(688, 800));
    setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());
    add(keyboard1, new org.netbeans.lib.awtextra.AbsoluteConstraints(0, 540, -1, -1));

    backgroundImage.setIcon(new javax.swing.ImageIcon(getClass().getResource("/resources/enigmaMachine.png"))); // NOI18N
    add(backgroundImage, new org.netbeans.lib.awtextra.AbsoluteConstraints(0, 0, 690, -1));
}// </editor-fold>                        

public Keyboard getKeyBoard(){
    return this.keyboard1;
}

// Variables declaration - do not modify                     
private javax.swing.JLabel backgroundImage;
private GUI.Keyboard keyboard1;
// End of variables declaration                   

}

EnigmaMain：

import javax.swing.ImageIcon;

公共类 EnigmaMain 扩展 javax.swing.JFrame {

/**
 * Creates new form EnigmaMain
 */
public EnigmaMain() {
    initComponents();
}

/**
 * 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() {

    machine1 = new GUI.Machine();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    setFocusableWindowState(false);
    getContentPane().setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());
    getContentPane().add(machine1, new org.netbeans.lib.awtextra.AbsoluteConstraints(0, 0, -1, -1));

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

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

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            EnigmaMain window = new EnigmaMain();
            window.setVisible(true);
        }
    });
}

// Variables declaration - do not modify                     
private GUI.Machine machine1;
// End of variables declaration                   
}

Answer 1

你能解释一下为什么

setFocusableWindowState(false);

对于您正在尝试做的事情是必要的？

你试过不带它跑步吗？