java - 如何将值传递给菜单项单击时的旋转方法？

Question

我正在开发旋转图像的应用程序。当用户单击菜单项时，图像应该旋转。现在我已经实现了键盘监听器，其中当用户按从右到左的按钮时，它会移动，但我想更改该方法并希望根据菜单项单击。

现在它将度数变量传递给旋转方法，现在我想自定义它，并且当用户单击菜单项时它会传递值。我不知道该怎么办。

我的代码:

public class RotateIMGn extends JPanel {
  private static final long serialVersionUID = 1L;
  ImageIcon image = new ImageIcon("D://Workspace//ScaleImage//src//images//img.png");
  JLabel label = new JLabel(image);
  JPanel rotationPanel;
  final int WIDTH = 350;
  final int HEIGHT = 500;
  double degrees;

  public RotateIMGn() {

    setPreferredSize(new Dimension(446, 500));

    setFocusable(true);

    addKeyListener(new KeyboardListener());
    rotationPanel = new JPanel();
    rotationPanel = new turningCanvas();
    rotationPanel.setPreferredSize(new Dimension(image.getIconWidth(), image.getIconHeight()));
    add(rotationPanel);

    JMenuBar menuBar = new JMenuBar();
    add(menuBar);

    JMenu mnFile = new JMenu("Rotate");
    menuBar.add(mnFile);

    ImageIcon icon90 = createImageIcon("/images/images_Right.png");
    JMenuItem mntmTR90 = new JMenuItem("Rotate 90+", icon90);

    mntmTR90.addActionListener(new ActionListener() {

      @Override
      public void actionPerformed(ActionEvent arg0) {
        try {

        } catch (Exception e) {
          e.printStackTrace();
        }

      }
    });

    mnFile.add(mntmTR90);

    ImageIcon icon180 = createImageIcon("/images/images_Vertical.png");
    JMenuItem mntmRT180 = new JMenuItem("Rotate 180+", icon180);
    mnFile.add(mntmRT180);

    JSeparator separator = new JSeparator();
    mnFile.add(separator);

    ImageIcon micon90 = createImageIcon("/images/images_Left.png");
    JMenuItem mntmTRM90 = new JMenuItem("Rotate 90-", micon90);
    mnFile.add(mntmTRM90);

    ImageIcon micon180 = createImageIcon("/images/images_Horizontal.png");
    JMenuItem mntmRTM180 = new JMenuItem("Rotate 180-", micon180);
    mnFile.add(mntmRTM180);
    rotationPanel.setBounds(WIDTH / 2, HEIGHT / 2,
        rotationPanel.getPreferredSize().width,

        rotationPanel.getPreferredSize().height);
    degrees = 0;
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g);
  }

  public class turningCanvas extends JPanel {
    private static final long serialVersionUID = 1L;

    public void paintComponent(Graphics g) {
      super.paintComponent(g);
      Graphics2D g2d = (Graphics2D) g;
      g2d.rotate(Math.toRadians(degrees), image.getIconWidth() / 2,
          image.getIconHeight() / 2);
      image.paintIcon(this, g2d, 0, 0);

    }
  }

  public class KeyboardListener implements KeyListener {
    public void keyPressed(KeyEvent event) {
      if (event.getKeyCode() == KeyEvent.VK_LEFT) {
        degrees--;
        repaint();
      }
      if (event.getKeyCode() == KeyEvent.VK_RIGHT) {
        degrees++;
        repaint();
      }
    }

    public void keyTyped(KeyEvent event) {
    }

    public void keyReleased(KeyEvent event) {
    }
  }

  public static void main(String[] args) {
    RotateIMGn test = new RotateIMGn();
    JFrame frame = new JFrame();
    frame.setContentPane(test);
    frame.pack();
    frame.setVisible(true);
  }

  protected static ImageIcon createImageIcon(String path) {
    java.net.URL imgURL = RotateIMGn.class.getResource(path);
    if (imgURL != null) {
      return new ImageIcon(imgURL);
    } else {
      System.err.println("Couldn't find file: " + path);
      return null;
    }
  }
}

anyone's idea will help me a lot so...

Answer 1

对菜单项使用 Swing Action 而不是 String。然后，在 actionPerformed 方法中，更新 levels 变量，就像您对 KeyListener 进行操作一样。

类似于:

ImageIcon icon90 = createImageIcon("/images/images_Right.png");
JMenuItem mntmTR90 = new JMenuItem(new AbstractAction("Rotate 90+", icon90) {
    public void actionPerformed(ActionEvent e) {
        degrees += 90;
        repaint();
    }
});