Làm cách nào để sử dụng KeyEventDispatcher

Question

Tôi đã cố gắng tạo một bản sao Pong như một dự án của người mới bắt đầu, và tôi đã đánh một khối đường. Tôi đã quản lý để có được đến điểm hỗ trợ bàn phím, nhưng sự chậm trễ lặp lại bàn phím đá vào. Tôi đã không tìm thấy bất kỳ cách nào có thể sử dụng để sử dụng KeyEventDispatcher. Nó thậm chí sẽ không khởi tạo phương thức dispatchKeyEvent(). Làm thế nào tôi sẽ đi về việc sử dụng này?

Xin cảm ơn trước.

PS: Đây là nguồn của tôi cho đến nay: http://pastebin.com/N9fLMzFT

Answer 1

bạn phải tìm kiếm KeyBindings

import java.awt.*; 
import java.awt.event.*; 
import java.awt.image.BufferedImage; 
import java.io.IOException; 
import java.net.*; 
import java.util.HashMap; 
import java.util.Map; 
import javax.imageio.ImageIO; 
import javax.swing.*; 

public class MoveIcon extends JPanel { 

    private static final long serialVersionUID = 1L; 
    private static final String IMAGE_PATH = "http://duke.kenai.com/misc/Bullfight.jpg"; 
    private static final String IMAGE_PATH_PLAYER = "http://duke.kenai.com/iconSized/duke4.gif"; 
    public static final int STEP = 3; 
    private static final int TIMER_DELAY = STEP * 8; 
    private BufferedImage bkgrndImage = null; 
    private BufferedImage playerImage = null; 
    private Map<Direction, Boolean> directionMap = new HashMap<Direction, Boolean>(); 
    private int playerX = 0; 
    private int playerY = 0; 

    enum Direction { 

     UP(KeyEvent.VK_UP, 0, -1), DOWN(KeyEvent.VK_DOWN, 0, 1), 
     LEFT(KeyEvent.VK_LEFT, -1, 0), RIGHT(KeyEvent.VK_RIGHT, 1, 0); 
     private int keyCode; 
     private int xDirection; 
     private int yDirection; 

     private Direction(int keyCode, int xDirection, int yDirection) { 
      this.keyCode = keyCode; 
      this.xDirection = xDirection; 
      this.yDirection = yDirection; 
     } 

     public int getKeyCode() { 
      return keyCode; 
     } 

     public int getXDirection() { 
      return xDirection; 
     } 

     public int getYDirection() { 
      return yDirection; 
     } 
    } 

    public MoveIcon() { 
     try { 
      URL bkgrdImageURL = new URL(IMAGE_PATH); 
      URL playerImageURL = new URL(IMAGE_PATH_PLAYER); 
      bkgrndImage = ImageIO.read(bkgrdImageURL); 
      playerImage = ImageIO.read(playerImageURL); 
      setPreferredSize(new Dimension(bkgrndImage.getWidth(), bkgrndImage.getHeight())); 
     } catch (MalformedURLException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
     for (Direction direction : Direction.values()) { 
      directionMap.put(direction, false); 
     } 
     setKeyBindings(); 
     Timer timer = new Timer(TIMER_DELAY, new TimerListener()); 
     timer.start(); 
    } 

    private void setKeyBindings() { 
     InputMap inMap = getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW); 
     ActionMap actMap = getActionMap(); 
     for (final Direction direction : Direction.values()) { 
      KeyStroke pressed = KeyStroke.getKeyStroke(direction.getKeyCode(), 0, false); 
      KeyStroke released = KeyStroke.getKeyStroke(direction.getKeyCode(), 0, true); 
      inMap.put(pressed, direction.toString() + "pressed"); 
      inMap.put(released, direction.toString() + "released"); 
      actMap.put(direction.toString() + "pressed", new AbstractAction() { 

       private static final long serialVersionUID = 1L; 

       @Override 
       public void actionPerformed(ActionEvent e) { 
        directionMap.put(direction, true); 
       } 
      }); 
      actMap.put(direction.toString() + "released", new AbstractAction() { 

       private static final long serialVersionUID = 1L; 

       @Override 
       public void actionPerformed(ActionEvent e) { 
        directionMap.put(direction, false); 
       } 
      }); 
     } 

    } 

    @Override 
    protected void paintComponent(Graphics g) { 
     super.paintComponent(g); 
     if (bkgrndImage != null) { 
      g.drawImage(bkgrndImage, 0, 0, null); 
     } 
     if (playerImage != null) { 
      g.drawImage(playerImage, playerX, playerY, null); 
     } 
    } 

    private class TimerListener implements ActionListener { 

     @Override 
     public void actionPerformed(ActionEvent e) { 
      boolean moved = false; 
      for (Direction direction : Direction.values()) { 
       if (directionMap.get(direction)) { 
        playerX += STEP * direction.getXDirection(); 
        playerY += STEP * direction.getYDirection(); 
        moved = true; 
       } 
      } 
      if (moved) { 
       int x = playerX - 2 * STEP; 
       int y = playerY - 2 * STEP; 
       int w = playerImage.getWidth() + 4 * STEP; 
       int h = playerImage.getHeight() + 4 * STEP; 
       MoveIcon.this.repaint(x, y, w, h); // !! repaint just the player 
      } 
     } 
    } 

    private static void createAndShowUI() { 
     JFrame frame = new JFrame("MoveIcon"); 
     frame.getContentPane().add(new MoveIcon()); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.pack(); 
     frame.setLocationRelativeTo(null); 
     frame.setVisible(true); 
    } 

    public static void main(String[] args) { 
     java.awt.EventQueue.invokeLater(new Runnable() { 

      @Override 
      public void run() { 
       createAndShowUI(); 
      } 
     }); 
    } 
}