SceneManager Implementierung

public class SceneManager : DrawableGameComponent
{
    public SceneManager(Game game)
        : base(game)
    {
        Scenes = new Dictionary<int,SceneBase>();
    }

    /// <summary>
    /// Die derzeit aktive Szene
    /// </summary>
    public SceneBase ActiveScene { get; private set; }

    /// <summary>
    /// Die Auflistung aller Szenen
    /// </summary>
    public Dictionary<int, SceneBase> Scenes { get; private set; }

    /// <summary>
    /// Fügt eine neue Szene mit einem Key hinzu
    /// </summary>
    public void AddScene(int key, SceneBase scene)
    {
        Scenes[key] = scene;
    }

    /// <summary>
    /// Zeigt die Szene mit dem übergebenen Key an
    /// </summary>
    public void ShowScene(int key)
    {
        if (ActiveScene != null)
            ActiveScene.Hide();

        ActiveScene = Scenes[key];
        ActiveScene.Show();
    }

    public override void Update(GameTime gameTime)
    {
        if(ActiveScene != null)
            ActiveScene.Update(gameTime);

        base.Update(gameTime);
    }

    public override void Draw(GameTime gameTime)
    {
        if (ActiveScene != null)
            ActiveScene.Draw(gameTime);

        base.Draw(gameTime);
    }
}