private void GamePage_Loaded(object sender, RoutedEventArgs e)
        {
            if (!pageLoaded)
            {
                manager = SharedGraphicsDeviceManager.Current;
                manager.PreferredBackBufferWidth = (int)this.ActualWidth;
                manager.PreferredBackBufferHeight = (int)this.ActualHeight;
                manager.SwapChainPanel = this;
                manager.ApplyChanges();

                gameTimer = new GameTimer();
                gameTimer.UpdateInterval = TimeSpan.FromTicks(166666);
                gameTimer.Update += Update;
                gameTimer.Draw += Draw;

                this.SizeChanged += GamePage_SizeChanged;

                // Le contenu est chargé une fois
                LoadContent();

                pageLoaded = true;
            }

            // L'initialisation doit se faire à chaque rechargement
            Initialize();
        }