in MvcMusicStore/Controllers/ShoppingCartController.cs [33:47]
public ActionResult AddToCart(int id)
{
// Retrieve the album from the database
var addedAlbum = storeDB.Albums
.Single(album => album.AlbumId == id);
// Add it to the shopping cart
var cart = ShoppingCart.GetCart(this.HttpContext);
cart.AddToCart(addedAlbum);
// Go back to the main store page for more shopping
return RedirectToAction("Index");
}