例如下面:
12345678910111213141516171819202122232425262728293031323334353637class PanelM extends JPanel{ImageIcon icon = new ImageIcon("app.gif") JLabel jl = new JLabel(icon, SwingConstants.CENTER) int x, yprivate List<Integer>listX = new ArrayList<Integer>() private List<Integer>listY = new ArrayList<Integer>()public PanelM(){add(jl) addMouseListener(new MouseAdapter(){public void mousePressed(MouseEvent m){x = m.getX() y = m.getY()listX.add(x) listY.add(y)repaint() }}) } public void paintComponent(Graphics g){ super.paintComponent(g) for (int i = 0i <listX.size()i++){g.fillOval(listX.get(i), listY.get(i), 20, 20) }}}
如果你是的Eclipse下面编辑运行java程序的话可以 运行Debug,然后设置断点,程序会一直运行到你设置的断点的地方停下来。之后你就可以进行单步运行了,可以边执行,边查看变量的值。