Java-Swing中的mouseMoved（）事件处理

Question

我想在JFrame中听鼠标移动和单击。为此，我添加了一个实现如下的MouseListener ：（
View类的整个代码在https://gist.github.com/2837224，Board类在https://gist.github.com/2837231）

class BattleshipsFrame extends JFrame {
  private final Board playerBoard, opponentBoard;
  private View view;

/** Main window constructor. */
BattleshipsFrame() {
  ...
  ...   
  ...
  //creating and displaying boards
  playerBoard = new Board();
  opponentBoard = new Board();
  PlayerBoardListener mouseListener = new PlayerBoardListener();
  this.addMouseListener(mouseListener);
  playerBoard.addMouseListener(mouseListener);
  opponentBoard.addMouseListener(new OpponentBoardListener());
  boards.add(playerBoard);
  boards.add(opponentBoard);
  ...
  ...
  ...
}

/** Listener responsible for handling mouse events on player board */
private class PlayerBoardListener extends MouseAdapter {
  @Override public void mousePressed(MouseEvent event) {
    try {
      if(event.getButton() == MouseEvent.BUTTON1 && controllerConnection != null)
        controllerConnection.sendShipPlacedEvent(event.getX()/40, event.getY()/40, ShipType.EMPTY);
    } catch(Exception e) {
      e.printStackTrace();
    }
  }   
  @Override public void mouseMoved(MouseEvent event) {
    //TODO
    System.out.println("Mouse movement detected! Actual mouse position is: " + event.getX()+ "," + event.getY() + ".");
  }   
  @Override public void mouseDragged(MouseEvent event) {
    //TODO
    System.out.println("Mouse movement detected! Actual mouse position is: " + event.getX()+ "," + event.getY() + ".");
  }

}

有趣的是，mousePressed（）运行良好，但其他两个运行不正常（移动鼠标时控制台上没有任何显示）。有人可以告诉我我在做什么错吗？提前致谢！

Answer 1

如果您想接收mouseMoved和mouseDragged事件，还需要将侦听器注册为MouseMotionListener。

MouseAdapter adapter = ...
JFrame frame = ...
frame.addMouseListener(adapter);
frame.addMouseMotionListener(adapter);