小编Jos*_*hua的帖子

我在框架内有一个JPanel.JPanel的内容应该在每次调用时更新paintComponent(调用方式repaint()),但是当我按照下面的方式调用时,我只看到一个白色的窗口.(请原谅那些破损的缩进,Eclipse会使用标签做各种奇怪的事情.)

private static void handleGUI() 
{       
    JFrame frame = new JFrame("Animation");
    frame.setPreferredSize(new Dimension(100, 100));

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Board b = new Board();

    frame.getContentPane().add(b);

    frame.pack();
    frame.setVisible(true);

    while(true)
    {
        System.out.println("Repainting panel");
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
        }
        b.repaint();
    }
}

public class Board extends JPanel
{
public Board() { t=0; }

    private int t;

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

    ++t;

    /* Variables snipped */

    g.setColor(Color.white);
    g.drawOval(0, 0, width, height);

    BufferedImage image = ImageIO.read(new File(imagePath));
    g.drawImage(image, x(t), …