如何在Main類的Jframe中添加KeyListener物件的JLabel

我對這種 Java 編碼有點陌生。問題是我有一個不同的 KeyListener 類和一個影像，如果用戶按下一個鍵，我想顯示一個影像，但影像來自 JLabel，我想將它添加到主類的 JFrame 中，但我不明白如何我會那樣做。是的，我確實看到了另一個問題，這個問題：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.util.HashMap;
import java.util.Map;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.Timer;
import javax.swing.border.LineBorder;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private Map<KeyHandler.Direction, JPanel> mapPanels;
        private KeyHandler keyHandler;

        public TestPane() {
            mapPanels = new HashMap<>();
            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;

            add(createPanel(KeyHandler.Direction.LEFT_UP), gbc);
            gbc.gridx  ;
            add(createPanel(KeyHandler.Direction.UP), gbc);
            gbc.gridx  ;
            add(createPanel(KeyHandler.Direction.RIGHT_UP), gbc);

            gbc.gridx = 0;
            gbc.gridy  ;
            add(createPanel(KeyHandler.Direction.LEFT), gbc);
            gbc.gridx  ;
            add(createPanel(), gbc);
            gbc.gridx  ;
            add(createPanel(KeyHandler.Direction.RIGHT), gbc);

            gbc.gridx = 0;
            gbc.gridy  ;
            add(createPanel(KeyHandler.Direction.LEFT_DOWN), gbc);
            gbc.gridx  ;
            add(createPanel(KeyHandler.Direction.DOWN), gbc);
            gbc.gridx  ;
            add(createPanel(KeyHandler.Direction.RIGHT_DOWN), gbc);
            
            keyHandler = new KeyHandler(getInputMap(WHEN_IN_FOCUSED_WINDOW), getActionMap(), new KeyHandlerListener() {
                @Override
                public void keyHandlerDidPress(KeyHandler.Direction direction) {
                    activate(direction);
                }
            });
        }
        
        protected JPanel createPanel() {
            JPanel panel = new JPanel() {
                @Override
                public Dimension getPreferredSize() {
                    return new Dimension(50, 50);
                }
            };
            panel.setBorder(new LineBorder(Color.DARK_GRAY));
            return panel;
        }

        protected JPanel createPanel(KeyHandler.Direction direction) {
            JPanel panel = createPanel();
            mapPanels.put(direction, panel);
            return panel;
        }
        
        protected void activate(KeyHandler.Direction direction) {
            JPanel panel = mapPanels.get(direction);
            panel.setBackground(Color.BLUE);
            Timer timer = new Timer(250, new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    panel.setBackground(null);
                }
            });
            timer.setRepeats(false);
            timer.start();
        }

    }

    public interface KeyHandlerListener {

        public void keyHandlerDidPress(KeyHandler.Direction direction);
    }

    public class KeyHandler {

        public enum Direction {
            UP, DOWN, LEFT, RIGHT,
            LEFT_UP, RIGHT_UP,
            LEFT_DOWN, RIGHT_DOWN
        }

        public KeyHandler(InputMap inputMap, ActionMap actionMap, KeyHandlerListener listener) {
            inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_Q, 0), "Press.leftUp");
            inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_W, 0), "Press.up");
            inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_E, 0), "Press.rightUp");
            inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_A, 0), "Press.left");
            inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_D, 0), "Press.right");
            inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_Z, 0), "Press.leftDown");
            inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_X, 0), "Press.down");
            inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_C, 0), "Press.rightDown");
            
            actionMap.put("Press.leftUp", new DirectionAction(Direction.LEFT_UP, listener));
            actionMap.put("Press.up", new DirectionAction(Direction.UP, listener));
            actionMap.put("Press.rightUp", new DirectionAction(Direction.RIGHT_UP, listener));
            actionMap.put("Press.left", new DirectionAction(Direction.LEFT, listener));
            actionMap.put("Press.right", new DirectionAction(Direction.RIGHT, listener));
            actionMap.put("Press.leftDown", new DirectionAction(Direction.LEFT_DOWN, listener));
            actionMap.put("Press.down", new DirectionAction(Direction.DOWN, listener));
            actionMap.put("Press.rightDown", new DirectionAction(Direction.RIGHT_DOWN, listener));
        }

        protected class DirectionAction extends AbstractAction {

            private Direction direction;
            private KeyHandlerListener listener;

            public DirectionAction(Direction direction, KeyHandlerListener listener) {
                this.direction = direction;
                this.listener = listener;
            }

            @Override
            public void actionPerformed(ActionEvent e) {
                listener.keyHandlerDidPress(direction);
            }

        }

    }
}

標籤：java swing keylistener

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