领域驱动设计实战案例（六）：订单上下文领域逻辑

DDD实战进阶第一波：开发一般业务的大健康行业直销系统

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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