import java.awt.*;
import javax.swing.*;
public class MainApp {
    public static void main(String args[]){
        GameControl gameControl = new GameControl();
        Environment gameBackground = new Environment();
        JFrame frame = new JFrame();
        frame.add(gameBackground,BorderLayout.CENTER);
        frame.setResizable(false);
        frame.setVisible(true); 
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(475,494);
        frame.setTitle("是男人就下一百层");
    }
}
class Environment extends JPanel{
    private Image background = new ImageIcon("backgroud.gif").getImage();
    Environment(){  
        setLayout(null);
        add(GameControl.boardPanel);  //注释了这行再运行的效果是我想达到的效果。。。
        //想知道为什么会出现这个BUG，而不仅仅是怎么修复这个bug
    }
    public void paintComponent(Graphics g){
        super.paintComponent(g);
        g.drawImage(background,0,0,getWidth(),getHeight(),this);
    }
}
class BoardPanel extends JPanel{
    BoardPanel(){
        setBounds(24,67,422,379);
    }
    public void paint(Graphics g){}
}
class GameControl implements Runnable{
    public static BoardPanel boardPanel = new BoardPanel(); 
    GameControl(){
        new Thread(this).start();
    }
    public void run(){
        while(true){
            try{
                Thread.sleep(30);
            }
            catch(InterruptedException e){
            }
            boardPanel.repaint();
        }
    }
}