长话短说，我正在使用我放在自定义JPanel中的BufferedImage绘制Mandelbrot。我已经在集合中进行了缩放，但是在取消缩放时重新绘制存在问题。取消缩放时，我将图像的值更改为图像的先前状态（我将每个状态都保留在堆栈中）并重新绘制面板。问题是堆栈中的最后一张图像被弹出，但它没有被绘制。

这些是我的实例变量

    private BufferedImage image = new BufferedImage(500, 500, BufferedImage.TYPE_INT_ARGB);  
    private Stack<BufferedImage> zooms = new Stack<BufferedImage>();  
    private boolean unzoom = false;  

这是我缩放和推送要保存在堆栈上的图像的方式

public void mouseReleased(MouseEvent e)
{
    zooms.push(image);
    <some code for zooming that works>
    repaint();
}  

现在我想通过滚动来取消缩放

class WheelZoomListener implements MouseWheelListener
{
    public void mouseWheelMoved(MouseWheelEvent e) 
    {
        unzoom = true;  
    //this is how I assign the current image to be the one before the last zoom
        image = zooms.pop();
        repaint();
    }
}  

最后这是我的作画方法

public void paintComponent(Graphics g)
{
    super.paintComponent(g);
    Graphics2D  g2d= (Graphics2D) g;  
     //if it is not unzooming draw the mandelbrot set normally by  
      //dealing with every pixel of the Buffered Image separately  
    if (!unzoom)
    {
        for(int i = 0; i < SIZE; i++)
        {
            for (int j = 0; j < SIZE; j++)
            {
                int iterations = getIterations(cnSet[i][j]);
                if (iterations == noIterations)
                {
                    color = Color.BLACK;
                }
                else
                {
                    color = cols[iterations%noIterations];
                }
                image.setRGB(i, j, color.getRGB());
            }
        }
    }  
//zooming or unzooming always draw the image in its current state
    g2d.drawImage(image, 0, 0, this);
    unzoom = false;
}  

FIX：原来我不需要每次都保留最后一张图像和创建临时图像。相反，现在我只将复杂平面的坐标保存在堆栈中。这就是我重新绘制旧图像所需的全部内容。