Database Reference
In-Depth Information
Listing 12-4.
Using the AssociationChanged Event to Keep the CartTotal in Sync with the Items in the Cart
class Program
{
static void Main(string[] args)
{
RunExample();
}
static void RunExample()
{
using (var context = new EFRecipesEntities())
{
var item1 = new CartItem { SKU = "AMM-223", Quantity = 3,
Price = 19.95M };
var item2 = new CartItem { SKU = "CAMP-12", Quantity = 1,
Price = 59.95M };
var item3 = new CartItem { SKU = "29292", Quantity = 2,
Price = 4.95M };
var cart = new Cart { CartTotal = 0 };
cart.CartItems.Add(item1);
cart.CartItems.Add(item2);
cart.CartItems.Add(item3);
context.Carts.AddObject(cart);
item1.Quantity = 1;
context.SaveChanges();
}
using (var context = new EFRecipesEntities())
{
foreach (var cart in context.Carts)
{
Console.WriteLine("Cart Total = {0}",
cart.CartTotal.ToString("C"));
foreach (var item in cart.CartItems)
{
Console.WriteLine("\tSKU = {0}, Qty = {1}, Unit Price = {2}",
item.SKU, item.Quantity.ToString(),
item.Price.ToString("C"));
}
}
}
}
}
public partial class Cart
{
public Cart()
{
this.CartItems.AssociationChanged += (s, e) =>
{
if (e.Action == CollectionChangeAction.Add)
