如何从另一个类的主类更改枚举值

Question

I'm trying to make a start menu for my game and my code uses Enum's to moniter the screen state.

Now i want to change the screenstate declared in the main class, in my Background class

Screen screen = new Screen();

is declared in the Game1 class

Background(ref screen);

This is in the update method for the Background Class

KeyboardState keystate = Keyboard.GetState();
switch (screen)
{
    case Screen.Start:
        if (isPressed && keystate.IsKeyUp(Keys.Up) && keystate.IsKeyUp(Keys.Down) && keystate.IsKeyUp(Keys.Enter))
        {
            isPressed = false;
        }
        if (keystate.IsKeyDown(Keys.Down) && isPressed != true)
        {
            if (menuState == MenuState.Options)
                menuState = MenuState.Credits;
            if (menuState == MenuState.Play)
                menuState = MenuState.Options;
            isPressed = true;
        }

        if (keystate.IsKeyDown(Keys.Up) && isPressed != true)
        {
            if (menuState == MenuState.Options)
                menuState = MenuState.Play;
            if (menuState == MenuState.Credits)
                menuState = MenuState.Options;
            isPressed = true;
        }

        switch (menuState)
        {
            case MenuState.Play:
                arrowRect.X = 450;
                arrowRect.Y = 220;
            if (keystate.IsKeyDown(Keys.Enter) && isPressed != true)
                screen = Screen.Play;
                break;
            case MenuState.Options:
                arrowRect.X = 419;
                arrowRect.Y = 340;
                if (keystate.IsKeyDown(Keys.Enter) && isPressed != true)
                    screen = Screen.Options;
                    break;
            case MenuState.Credits:
                arrowRect.X = 425;
                arrowRect.Y = 460;
                if (keystate.IsKeyDown(Keys.Enter) && isPressed != true)
                    screen = Screen.Credits;
                break;
            }
            break;
       }
 }

For some reason when I play this and I hit the enter button the Background class's screen is changed but the main class's screen isn't how can i change this?

Answer 1

Maybe you're doing something wrong somewhere else, this code seems correct.

You can bypass this problem adding a GetState() method in your Background class, and call it in your Game1 Update method, without using ref screen .

EDIT

If screen is an enum I think you can't pass it like a reference, because

System.Enum is a reference type, but any specific enum type is a value type.