java - GUI 不更新简单游戏中的值

Question

我正在使用 Swing 库制作一个简单的 2d 平台游戏，我试图在 GUI 中不断显示不同的值。这些值在第一个级别中更新并完美运行，但在下一个级别中它们保持不变。

GUI 代码:

public class MyView extends UserView {

    Player player;

    private Image background;
    private Image newBackground;

    public MyView(World world, Player player, int width, int height) {
        super(world, width, height);
        this.player = player;
        this.background = new ImageIcon("data/rainy.gif").getImage()
                .getScaledInstance(1000, 1000, 1000);
    }

    @Override
    protected void paintForeground(Graphics2D g) {
        g.drawString("Lives left: " + player.getLifeCount(), 650, 20);
        g.drawString("Blue hearts picked: " + player.getBlueHeartCount(), 650, 30);
        g.drawString("Time left: " + player.getTimeCounter(), 650, 50);
     }
    }

到达第二层时，player.getLifeCount()、player.getBlueHeartCount() 和 player.getTimeCounter() 卡住并停止更新。

以下是级别 1 和级别 2 的相关代码(未导入)，其中值已更改:

public class Level1 extends GameLevel implements ActionListener {

@Override
    public void actionPerformed(ActionEvent e) {
        if (getPlayer().heartPick) {
            timer.stop();
        } else if (player.getTimeCounter() <= 0) {
            System.exit(0);
        } else {
            counter -= 1;
            player.setTimeCounter(counter);
        }
    }

2 级代码:

public class Level2 extends GameLevel implements ActionListener {

@Override
    public void actionPerformed(ActionEvent e) {
//        System.out.println("Action event!");
        if (getPlayer().heartPick) {
            timer.stop();
        } else if (player.getTimeCounter() <= 0) {
            System.exit(0);
        } else {
            counter -= 1;
            player.setTimeCounter(counter);
        }
    }
}

下面是主类的相关代码:

public class Game {
    private GameLevel world;

    private MyView view;

    private int level;

    // timer
    private Timer timer;

    public Game(){

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

        // make a view
        view = new MyView(world, world.getPlayer(), 800, 600);

        // display the view in a frame
        final JFrame frame = new JFrame("Event handling");

        // start!
        world.start();
    }

    // return world
    public GameLevel getWorld() {
            return world;
    }

    // the player in current level
    public Player getPlayer() {
        return world.getPlayer();
    }

    // Progress to next level
    public void goNextLevel() {
        world.stop();

        switch (level) {
            case 4:
                System.exit(0);
            case 2:
                level++;

                // get a new world
                world = new Level2();

                // fill world
                world.populate(this);

                // show the new world in the view
                view.setWorld(world);

                view.setBackground(2);
                world.start();
                break;

            case 3:
                level++;

                //get new world
                world = new Level3();

                //fill world
                world.populate(this);

                // show the new world in the view
                view.setWorld(world);

                view.setBackground(3);
                world.start();
                break;

            default:
                level++;
                break;

        }
    }
}

Answer 1

goNextLevel 中的 switch 语句是根据您将要进入的级别而不是当前所在的级别进行切换的。因此，当您处于第 1 级并点击 goNextLevel block 时，它会转到 default。您希望根据曾经的级别而不是将来的级别进行切换，因为您正在该语句中更新它。