DDD实战进阶第一波：开发一般业务的大健康行业直销系统

上一篇文章我们主要讲了订单上下文的领域逻辑，在领域逻辑中完成了订单项的计算逻辑、订单的计算逻辑以及如何生成相应的实体code，这篇文章我们通过在应用服务中实现一个下单的用例，来将这些领域逻辑以及仓储整合起来，完成一个下单的用例。

先看下单用例主体的代码：

public class CreateOrderUseCase:BaseAppSrv

{    private readonly IOrderRepository iorderrepository;    private readonly IDealerRepository idealerrepository;    private readonly IRepository[] irepositories;        public CreateOrderUseCase(IOrderRepository iorderrepository,IDealerRepository idealerrepository,        params IRepository[] irepositories)    {        this.iorderrepository = iorderrepository;        this.idealerrepository = idealerrepository;        this.irepositories = irepositories;    }    public ResultEntity
    
      CreateOrder(OrderDTO orderdto)    {        var orderid = Guid.NewGuid();        Orders order = new Orders();        var productskus = new List
     
      ();        for(int i = 0; i < orderdto.ProductSPUNames.Count; i++)        {            var productsku = new ProductSKU();            productsku.ProductSPUName = orderdto.ProductSPUNames[i];            productsku.DealerPrice = orderdto.ProductDealerPrices[i];            productsku.PV = orderdto.ProductPVS[i];            productsku.Id = orderdto.ProductSKUIds[i];            productsku.Spec = orderdto.ProductSepcs[i];            productskus.Add(productsku);        }        var contact = new Contact();        contact.ContactName = orderdto.ContactName;        contact.ContactTel = orderdto.ContactTel;        contact.Province = orderdto.Privence;        contact.City = orderdto.City;        contact.Zero = orderdto.Zero;        contact.Street = orderdto.Street;        var orders = order.CreateOrders(orderid, orderdto.DealerId, productskus, orderdto.Counts,            contact);        try        {            //using (var tansaction = new TransactionScope())            //{                using (irepositories[1])                {                    idealerrepository.SubParentEleMoney(orderdto.DealerId, order.OrderTotalPrice.TotalPrice);                    idealerrepository.AddDealerPV(orderdto.DealerId, order.OrderTotalPV.TotalPV);                    irepositories[1].Commit();                }                using (irepositories[0])                {                    iorderrepository.CreateOrder(orders);                    irepositories[0].Commit();                }            return GetResultEntity(true);                //tansaction.Complete();            //}        }        catch(EleMoneyNotEnoughException error)        {            throw error;        }        catch(Exception error)        {            throw error;        }            }}
     
    

IOrderRepository仓储接口主要完成订单的预持久化工作，我们来看下它的实现：

public class OrderEFCoreRepository : IOrderRepository

{    private readonly DbContext context;            public OrderEFCoreRepository(DbContext context)    {        this.context = context;    }    public void CreateOrder
    
     (T order) where T:class,IAggregationRoot    {        var ordercontext = this.context as OrderEFCoreContext;        var ordernew = order as Orders;        try        {            ordercontext.Order.Add(ordernew);        }        catch(Exception error)        {            throw error;        }    }
    

}

IDealerRepository仓储接口主要用来下单完成后，扣减对应经销商的电子币与累加PV，相关方法实现代码如下：

public void SubParentEleMoney(Guid parentdealerid, decimal subelemoney)

{        var dealercontext = this.context as DealerEFCoreContext;        var parentdealer = dealercontext.Dealer.Single(p => p.Id == parentdealerid);        parentdealer.TotalEleMoney = parentdealer.TotalEleMoney - subelemoney;        if (parentdealer.TotalEleMoney < 0)        {            throw new EleMoneyNotEnoughException("电子币不够进行此操作!");        }        try        {            dealercontext.Entry(parentdealer).State = EntityState.Modified;        }        catch(Exception error)        {            throw error;        }    }    public void AddDealerPV(Guid dealerid, decimal orderpv)    {        var dealercontext = this.context as DealerEFCoreContext;        var dealer = dealercontext.Dealer.Single(p => p.Id == dealerid);        dealer.TotalPV = dealer.TotalPV +orderpv;        try        {            dealercontext.Entry(dealer).State = EntityState.Modified;        }        catch (Exception error)        {            throw error;        }    }

IRepository[]用于订单与经销商两个的数据访问仓储，完成真正的持久化，在第一部分主体代码中注释掉的using (var tansaction = new TransactionScope())与

tansaction.Complete();是因为在.net core 2.0版本中，不支持多个数据访问上下文的事务，在.net core 2.1版本中可以使用，这样就完成了订单数据与经销商数据的事务一致性。

最后我们通过webapi完成对应用服务的调用，实现代码如下。

[HttpPost]

[Route("CreateOrder")]    public ResultEntity
    
      CreateOrder([FromBody] OrderDTO orderdto)    {        var result = new ResultEntity
     
      ();        var ordercontext = new OrderEFCoreContext();        var dealercontext = new DealerEFCoreContext();        var irepository = new EFCoreRepository(ordercontext);        var irepository1 = new EFCoreRepository(dealercontext);        var iorderrepository = new OrderEFCoreRepository(ordercontext);        var idealerrepository = new DealerEFCoreRepository(dealercontext);        var createorderusecase = new CreateOrderUseCase(iorderrepository, idealerrepository,            irepository, irepository1);        try        {            result = createorderusecase.CreateOrder(orderdto);            result.Count = 1;            result.IsSuccess = true;            result.Msg = "下单成功!";        }        catch (EleMoneyNotEnoughException error)        {            result.ErrorCode = 300;            result.Msg = error.Message;        }        catch (Exception error)        {            result.ErrorCode = 200;            result.Msg = error.Message;        }        return result;    }
     
    

因为这里只是做演示，具体接口与实现没有通过依赖注入框架注入，这部分内容可以自己去实现。

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