鼠標的座標？

Question

public class mouse extends JFrame { 
    private int x, y; 
    private JLabel label; 

    public mouse() { 
     JPanel panel = new JPanel(); 
     addMouseMotionListener(new MouseMotion()); 
     label = new JLabel(); 
     panel.add(label); 
     setPreferredSize(new Dimension(400, 200)); 
     add(panel, BorderLayout.SOUTH); 
     pack(); 
     setVisible(true); 
    } 
    private class MouseMotion extends MouseMotionAdapter { 
     public void mouseMoved(MouseEvent e) { 
      x = e.getX(); 
      y = e.getY(); 
      label.setText("mouse coordinate " + "(" + x + "," + y + ")"); 
    }} 
    public static void main(String[]args) { 
     mouse a = new mouse(); 
    } 
} 

當我將鼠標移動到邊界時，它不是（0,0）。爲什麼？例如，我將鼠標移動到左上角，它顯示（4,30）而不是（0,0）。

Answer 1

將MouseListener或MouseMotionListener添加到JFrame的contentPane，而不是JFrame本身，否則您不得不擔心邊框，菜單，插圖等等。例如：

getContentPane().addMouseMotionListener(new MouseMotion()); 

此外，請格式化您的代碼，以便我們可以閱讀它。