Java在循环中实例化类

Question

我在Java中实例化一个类时遇到了一个问题，本质上它每一次都会生成一个新的世界，这在程序运行时有点令人沮丧。 而我需要做的就是实例化它，然后访问类中的一个变量

以下是代码：

背景。爪哇

public class Background extends UserView {
    private BufferedImage bg;    

    private static Game game;    

    public Background(World w, int width, int height) {        
        super(w, width, height);
        try {
            bg = ImageIO.read(new File("data/background.jpg")); 
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void paintBackground(Graphics2D g) {        
        super.paintBackground(g);  
        game = new Game();
        g.drawImage(bg, 0, 0, this);   
        int level = game.getLevel();
        g.drawString("Level: " + level, 25, 25);
    }

}

游戏。爪哇

public Game() {
    // make the world
    level = 1;
    world = new Level1();
    world.populate(this);

    // make a view
    view = new Background(world, 500, 500);     

    // uncomment this to draw a 1-metre grid over the view
    // view.setGridResolution(1);

    // display the view in a frame
    JFrame frame = new JFrame("Save the Princess");

    // quit the application when the game window is closed
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocationByPlatform(true);
    // display the world in the window
    frame.add(view);
    // don't let the game window be resized
    frame.setResizable(false);
    // size the game window to fit the world view
    frame.pack();
    // make the window visible
    frame.setVisible(true);
    // get keyboard focus
    frame.requestFocus();
    // give keyboard focus to the frame whenever the mouse enters the view
    view.addMouseListener(new GiveFocus(frame));

    controller = new Controller(world.getPlayer());
    frame.addKeyListener(controller);

    // start!
    world.start();
}

   /** Run the game. */
public static void main(String[] args) {
    new Game();
}

任何帮助都将不胜感激！谢谢!

Answer 1

你可能需要考虑类的概念和它的依赖关系，但在你的情况下，这是最简单、最快的方法，只保留一个游戏实例：

public class Background extends UserView {

    private BufferedImage bg;

    private static Game game = new Game();

    public Background(World w, int width, int height) {
        super(w, width, height);
        try {
            bg = ImageIO.read(new File("data/background.jpg"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void paintBackground(Graphics2D g) {
        super.paintBackground(g);
        g.drawImage(bg, 0, 0, this);
        int level = game.getLevel();
        g.drawString("Level: " + level, 25, 25);
    }
}

如果你添加更多代码，说出你想要什么，得到什么，我们可以告诉你更多