Hi i got the way to update the cart
// create a reference to the Hotcakes store
var HccApp = HccAppHelper.InitHccApp();
// get an instance of the product to add
var p = HccApp.CatalogServices.Products.Find(bvin);
// create a reference to the current shopping cart
Order currentCart = HccApp.OrderServices.EnsureShoppingCart();
try
{
foreach (LineItem lineItem in currentCart.Items)
{
if (lineItem.ProductId.ToString() == bvin.ToString())
{
if (Convert.ToInt32(qty) == 0)
{
currentCart.Items.Remove(lineItem);
HccApp.CalculateOrderAndSave(currentCart);
}
else
{
lineItem.Quantity = lineItem.Quantity - 1;
HccApp.CalculateOrderAndSave(currentCart);
}
}
}
}
catch
{
}