领域驱动设计实战进阶第一波（十四）：订单上下文应用服务用例与接口
DDD实战进阶第一波(十四)：开发一般业务的大健康行业直销系统（订单上下文应用服务用例与接口）
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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