How to control the back key in cocos2d-xna game to achieve Objective jump

In actual situations, we sometimes need to determine the "scenario" of WP based on different game scenarios ".

Therefore, we can first create a constant class with a constant in it to mark the representative values of different pages,

For example:

class GameMain    {        public static int CurrentScreen;    }

Then assign a value to the class constructor in different scenarios.

class ChooseScreen : CCScene    {        private static ChooseScreen _current;        public static ChooseScreen Current        {            get            {                GameMain.CurrentScreen = 1;                if (_current == null)                {                    _current = new ChooseScreen();                }                return _current;            }        }        private ChooseScreen()        {            this.addChild(new ChooseLayer());        }    }

Finally, rewrite the function in game1.cs.

protected override void Update(GameTime gameTime)        {            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)            {                switch (GameMain.CurrentScreen)                {                    case -1:                    case 0:                        this.Exit();                        break;                    case 1:                        CCDirector.sharedDirector().replaceScene(MainMenuScreen.Current);                        break;                    case 2:                        string msg = "Quit Game?";                        List<string> MBButtons = new List<string>();                        MBButtons.Add("Yes");                        MBButtons.Add("No");                        Guide.BeginShowMessageBox("Game Over", msg, MBButtons, 0,                                            MessageBoxIcon.Alert, GetMBResult, null);                        break;                    default:                        this.Exit();                        break;                }            }            base.Update(gameTime);        }

void GetMBResult(IAsyncResult r)
        {
            int? b = Guide.EndShowMessageBox(r);
            if (b == 0)
            {
                CCDirector.sharedDirector().replaceScene(ChooseScreen.Current);
            }
        }

Complete.