如何在Scene2D libGDX中更改屏幕

Question

I've been searching around Google for tutorials on how to use multiple screens with LibGDX using Scene2D. So far this is what I have in my Scene handling class but I don't know where to go from here. I know I have to do something to the constructor of MainMenu.java but I don't know what it is.

What I've got so far:

public class ScreenHandler extends Game{
    public MainMenu Main;
    @Override
    public void create() {
          Main= new MainMenu();
          setScreen(Main);

    }

}

Answer 1

I'm not a big fan of making my screen classes coupled to my Game class. The approach that I'm using is an abstract class for all of my game's screens which has aa flag and functionality to indicate that a "next screen" is being requested. The render method of my Game class can then check for that flag and render a new screen accordingly.

public class MyGame extends Game {

    // ...

    @Override
    public void create() {
        GameScreen screen1 = new GameScreen(); // extends AbstractScreen
        GameScreen screen2 = new GameScreen(); // extends AbstractScreen
        screen1.setNextScreen(screen2);
        screen2.setBackScreen(screen1);
    }

    @Override
    public void render() {
        AbstractScreen currentScreen = (AbstractScreen) getScreen();

        if (currentScreen.goBack) {
            setScreen(currentScreen.getBackScreen());
        } else if (currentScreen.goToNextScreen) {
            setScreen(currentScreen.getNextScreen());
        }
    }

In practice I wouldn't actually instantiate all the screens in the create method but instead have methods for creating/disposing screens as needed, but, the above is a simplification of the general idea.

Then the individual screens are responsible for setting the goBack and goToNextScreen flags as necessary.

Answer 2

I know this is old, but just want to point out that accepted answer WILL NOT render; just got tied up on this for 2 hrs...

// ...


@Override
public void render() {
    AbstractScreen currentScreen = (AbstractScreen) getScreen();

    if (currentScreen.goBack) {
        setScreen(currentScreen.getBackScreen());
    } else if (currentScreen.goToNextScreen) {
        setScreen(currentScreen.getNextScreen());
    }
}

You MUST add a call to super.render() in a Game subclass if you override Game's render() method.

Answer 3

I found this link that explains exactly what I need! https://code.google.com/p/libgdx-users/wiki/ScreenAndGameClasses