DDD实战进阶第一波(十三)：开发一般业务的大健康行业直销系统（订单上下文领域逻辑）

前一篇文章主要讲了订单上下文的POCO模型，其中订单与订单项中有大量的值对象。这篇文章主要讲讲这些值对象以及订单项、订单相关的领域逻辑。

1.ProductSKUs值对象领域逻辑：
ProductSKUs值对象用于订单项实体中，它的信息应该来源于产品上下文的ProductSKU实体。

public partial class ProductSKUs
    {
        public ProductSKUs() { }
        public ProductSKUs CreateProductSKUs(ProductSKU productsku)
        {
            this.ProductSPUName = productsku.ProductSPUName;
            this.ProductPrice = productsku.DealerPrice;
            this.ProductPV = productsku.PV;
            this.ProductSKUId = productsku.Id;
            return this;
        }
    }

2.OrderItemTotalPV值对象领域逻辑：

OrderItemTotalPV值对象的领域逻辑主要是通过订单项购买的ProductSKU的PV与数量计算出这个订单项的总PV值。

public partial class OrderItemTotalPV
    {
        public OrderItemTotalPV() { }
        public OrderItemTotalPV CreateOrderItemTotalPV(ProductSKU productsku,int count)
        {
            this.SubTotalPV = productsku.PV * count;
            return this;
        }
    }

3.OrderItemTotalPrice值对象领域逻辑：

OrderItemTotalPrice值对象的领域逻辑主要是通过订单项购买的ProductSKU的单价与数量计算出这个订单项的总价。

 public partial class OrderItemTotalPrice
    {
        public OrderItemTotalPrice() { }
        public OrderItemTotalPrice CreateOrderItemTotalPrice(ProductSKU productsku,int count)
        {
            this.SubTotalPrice = productsku.DealerPrice * count;
            return this;
        }
    }

4.OrderItem实体的领域逻辑：

OrderItem实体的领域逻辑主要包含两个方面，一个是OrderItem的Code生成规则，二是调用自身包含的上述三个值对象领域逻辑，生成相关的值对象。

 public partial class OrderItem
    {
        public OrderItem() { }
        public OrderItem CreateOrderItem(ProductSKU productsku,int count)
        {
            this.Id = Guid.NewGuid();
            this.Code = "OrderItem " + DateTime.Now.ToString();
            this.Count = count;

            this.OrderItemTotalPrice = new OrderItemTotalPrice().CreateOrderItemTotalPrice(productsku,
                count);
            this.OrderItemTotalPV = new OrderItemTotalPV().CreateOrderItemTotalPV(productsku,
                count);
            this.ProductSKUs = new ProductSKUs().CreateProductSKUs(productsku);
            return this;
        }
    }

5.OrderStreet值对象领域逻辑：

OrderStreet值对象的信息主要由产品购买时，确定的联系人信息将相关的属性赋值给OrderStreet值对象。

 public partial class OrderStreet
    {
        public OrderStreet() { }
        public OrderStreet CreateOrderStreet(Contact contact)
        {
            this.Privince = contact.Province;
            this.City = contact.City;
            this.Zero = contact.Zero;
            this.Street = contact.Street;
            return this;
        }
    }

6.OrderTotalPV值对象领域逻辑：

OrderTotalPV值对象的值由每个订单项的OrderItemTotalPV值对象累加起来。

public partial class OrderTotalPV
    {
        public OrderTotalPV() { }
        public OrderTotalPV CreateOrderTotalPV(List<OrderItemTotalPV> itemtotalpvs)
        {
            var ordertotalpv = 0.00M;
            itemtotalpvs.ForEach(p =>
            {
                ordertotalpv += p.SubTotalPV;
            });
            this.TotalPV = ordertotalpv;
            return this;
        }
    }

7.OrderTotalPrice值对象领域逻辑：

OrderTotalPrice值对象的值由每个订单项的OrderItemTotalPrice值对象累加起来。

 public partial class OrderTotalPrice
    {
        public OrderTotalPrice() { }
        public OrderTotalPrice CreateOrderTotalPrice(List<OrderItemTotalPrice> itemtotalprices)
        {
            var ordertotalprice = 0.00M;
            itemtotalprices.ForEach(p =>
            {
                ordertotalprice += p.SubTotalPrice;
            });
            this.TotalPrice = ordertotalprice;
            return this;
        }
    }

8.Orders聚合根领域逻辑：

Orders聚合根其实就是协调OrderItem实体、自身包含的3个值对象完成整个下单的领域逻辑。

public Orders CreateOrders(Guid id,Guid dealerid,List<ProductSKU> productskus,
            List<int> counts,Contact contact)
        {
            this.Id = id;
            this.OrderDealerId = dealerid;
            this.OrderDateTime = DateTime.Now;
            this.Telephone = contact.ContactTel;
            this.Code = "Order " + DateTime.Now.ToString();

            this.OrderStreet = new OrderStreet().CreateOrderStreet(contact);
            this.OrderItems = new List<OrderItem>();
            var orderitemtotalprices = new List<OrderItemTotalPrice>();
            var orderitemtotalpvs = new List<OrderItemTotalPV>();
            for(int i = 0; i < productskus.Count; i++)
            {
                var orderitem = new OrderItem().CreateOrderItem(productskus[i], counts[i]);
                this.OrderItems.Add(orderitem);
                orderitemtotalprices.Add(orderitem.OrderItemTotalPrice);
                orderitemtotalpvs.Add(orderitem.OrderItemTotalPV);
            }
            this.OrderTotalPrice = new OrderTotalPrice().CreateOrderTotalPrice(orderitemtotalprices);
            this.OrderTotalPV = new OrderTotalPV().CreateOrderTotalPV(orderitemtotalpvs);
            return this;
        }

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