Game1.cs

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using System;
using System.Collections.Generic;

namespace GoGame
{

    public class Game1 : Game
    {
        #region Fields
        private State _currentState;
        private State _nextState;

        private GraphicsDeviceManager _graphics;
        private SpriteBatch _spriteBatch;
        #endregion

        public Game1()
        {
            _graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
            IsMouseVisible = true;
        }

        #region Methods

        protected override void Initialize()
        {
            base.Initialize();
        }

        protected override void LoadContent()
        {
            _spriteBatch = new SpriteBatch(GraphicsDevice);

            _currentState = new MenuState(this, _graphics, Content);
        }

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
                Exit();

            if (_nextState != null)
            {
                _currentState = _nextState;

                _nextState = null;
            }

            _currentState.Update(gameTime);
            _currentState.PostUpdate(gameTime);

            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(new Color(221, 180, 92, 1));

            _currentState.Draw(gameTime, _spriteBatch);

            base.Draw(gameTime);
        }

        public void ChangeState(State state)
        {
            _nextState = state;
        }

        #endregion

    }
}