Question

我试图制作一个简单的游戏，我需要检查是否按下了多个键。类似的问题得到了以下答案：

class MultiKeyPressListener implements KeyListener {

    // Set of currently pressed keys
    private final Set<Character> pressed = new HashSet<Character>();

    @Override
    public synchronized void keyPressed(KeyEvent e) {
        pressed.add(e.getKeyChar());
        if (pressed.size() > 1) {
            // More than one key is currently pressed.
            // Iterate over pressed to get the keys.
        }
    }

    @Override
    public synchronized void keyReleased(KeyEvent e) {
        pressed.remove(e.getKeyChar());
    }

    @Override
        public void keyTyped(KeyEvent e) {/* Not used */ }
    }
}

我如何＆＃34;迭代按下来获取密钥＆＃34;？我想出了以下内容：

// declarations

private final Set<Character> pressed = new HashSet<>();

// code

    @Override
    public synchronized void keyPressed(KeyEvent e) {               
        pressed.add(e.getKeyChar());

        if(pressed.contains(KeyEvent.VK_UP)) {  
            switch(e.getKeyCode()) {
            case KeyEvent.VK_LEFT: 
                starfighter.moveUpLeft();
                break;
            case KeyEvent.VK_RIGHT:
                starfighter.moveUpRight();
                break;
            }
        }
    }

但这不起作用。我怎样才能做到这一点？

由于

Answer 1

怎么样：

class MultiKeyPressListener implements KeyListener {

  // Set of currently pressed keys
  private final Set<Integer> pressed = new HashSet<Integer>();

  @Override
  public synchronized void keyPressed(KeyEvent e) {
    pressed.add(e.getKeyCode());

    if (pressed.contains(KeyEvent.VK_UP)) {
      if (pressed.contains(KeyEvent.VK_LEFT)) {
        starfighter.moveUpLeft();
      }
      if (pressed.contains(KeyEvent.VK_RIGHT)) {
        starfighter.moveUpRight();
      }
    }
  }

  @Override
  public synchronized void keyReleased(KeyEvent e) {
    pressed.remove(e.getKeyCode());
  }

  @Override
    public void keyTyped(KeyEvent e) {/* Not used */ }
  }
}

注意如何使用一组整数而不是字符并存储密钥代码而不是关键字符。

在Java中按下多个键

1 个答案: