private int _number = 0;public int Add(int factor){_number += factor;return _number;}

private int _number = 0;
private void AddCommand(int factor)
{_number += factor;
}private int QueryValue()
{return _number;
}

    // 应用程序初始化操作，将依赖的对象通过依赖注入框架StructureMap进行注入public sealed class ServiceLocator{private static readonly ICommandBus _commandBus;private static readonly IStorage _queryStorage;private static readonly bool IsInitialized;private static readonly object LockThis = new object();static ServiceLocator(){if (!IsInitialized){lock (LockThis){// 依赖注入
                    ContainerBootstrapper.BootstrapStructureMap();_commandBus = ContainerBootstrapper.Container.GetInstance<ICommandBus>();_queryStorage = ContainerBootstrapper.Container.GetInstance<IStorage>();IsInitialized = true;}}}public static ICommandBus CommandBus{get { return _commandBus; }}public static IStorage QueryStorage{get { return _queryStorage; }}}class ContainerBootstrapper{private static Container _container;public static void BootstrapStructureMap(){_container = new Container(x =>{x.For(typeof (IDomainRepository<>)).Singleton().Use(typeof (DomainRepository<>));x.For<IEventStorage>().Singleton().Use<InMemoryEventStorage>();x.For<IEventBus>().Use<EventBus>();x.For<ICommandBus>().Use<CommandBus>();x.For<IStorage>().Use<InMemoryStorage>();x.For<IEventHandlerFactory>().Use<StructureMapEventHandlerFactory>();x.For<ICommandHandlerFactory>().Use<StructureMapCommandHandlerFactory>();});}public static Container Container {get { return _container;}}}public class HomeController : Controller{[HttpPost]public ActionResult Add(DiaryItemDto item){// 发布CreateItemCommand到CommandBus中ServiceLocator.CommandBus.Send(new CreateItemCommand(Guid.NewGuid(), item.Title, item.Description, -1, item.From, item.To));return RedirectToAction("Index");}    }// CommandBus 的实现public class CommandBus : ICommandBus{private readonly ICommandHandlerFactory _commandHandlerFactory;public CommandBus(ICommandHandlerFactory commandHandlerFactory){_commandHandlerFactory = commandHandlerFactory;}public void Send<T>(T command) where T : Command{// 获得对应的CommandHandle来对命令进行处理var handlers = _commandHandlerFactory.GetHandlers<T>();foreach (var handler in handlers){// 处理命令
                handler.Execute(command);}}       }// 对CreateItemCommand处理类public class CreateItemCommandHandler : ICommandHandler<CreateItemCommand>{private readonly IDomainRepository<DiaryItem> _domainRepository;public CreateItemCommandHandler(IDomainRepository<DiaryItem> domainRepository){_domainRepository = domainRepository;}// 具体处理逻辑public void Execute(CreateItemCommand command){if (command == null){throw new ArgumentNullException("command");}if (_domainRepository == null){throw new InvalidOperationException("domainRepository is not initialized.");}var aggregate = new DiaryItem(command.ID, command.Title, command.Description, command.From, command.To){Version = -1};// 将对应的领域实体进行保存
            _domainRepository.Save(aggregate, aggregate.Version);}}// IDomainRepository的实现类public class DomainRepository<T> : IDomainRepository<T> where T : AggregateRoot, new(){// 并没有直接对领域实体进行保存，而是先保存领域事件进EventStore，然后在Publish事件到EventBus进行处理// 然后EventBus把事件分配给对应的事件处理器进行处理，由事件处理器来把领域对象保存到QueryDatabase中public void Save(AggregateRoot aggregate, int expectedVersion){if (aggregate.GetUncommittedChanges().Any()){_storage.Save(aggregate);}}}// Event Store的实现，这里保存在内存中，通常是保存到具体的数据库中，如SQL Server、Mongodb等public class InMemoryEventStorage : IEventStorage{// 领域事件的保存public void Save(AggregateRoot aggregate){// 获得对应领域实体未提交的事件var uncommittedChanges = aggregate.GetUncommittedChanges();var version = aggregate.Version;foreach (var @event in uncommittedChanges){version++;// 没3个事件创建一次快照if (version > 2){if (version % 3 == 0){var originator = (ISnapshotOrignator)aggregate;var snapshot = originator.CreateSnapshot();snapshot.Version = version;SaveSnapshot(snapshot);}}@event.Version = version;// 保存事件到EventStore中
                _events.Add(@event);}// 保存事件完成之后，再将该事件发布到EventBus 做进一步处理foreach (var @event in uncommittedChanges){var desEvent = TypeConverter.ChangeTo(@event, @event.GetType());_eventBus.Publish(desEvent);}}}// EventBus的实现public class EventBus : IEventBus{private readonly IEventHandlerFactory _eventHandlerFactory;public EventBus(IEventHandlerFactory eventHandlerFactory){_eventHandlerFactory = eventHandlerFactory;}public void Publish<T>(T @event) where T : DomainEvent{// 获得对应的EventHandle来处理事件var handlers = _eventHandlerFactory.GetHandlers<T>();foreach (var eventHandler in handlers){// 对事件进行处理
                eventHandler.Handle(@event);}}}// DiaryItemCreatedEvent的事件处理类public class DiaryIteamCreatedEventHandler : IEventHandler<DiaryItemCreatedEvent>{private readonly IStorage _storage;public DiaryIteamCreatedEventHandler(IStorage storage){_storage = storage;}public void Handle(DiaryItemCreatedEvent @event){var item = new DiaryItemDto(){Id = @event.SourceId,Description = @event.Description,From = @event.From,Title = @event.Title,To = @event.To,Version = @event.Version};// 将领域对象持久化到QueryDatabase中
            _storage.Add(item);}}

 public class HomeController : Controller{// 查询部分public ActionResult Index(){// 直接获得QueryDatabase对象来查询所有日志var model = ServiceLocator.QueryStorage.GetItems();return View(model);}}public class InMemoryStorage : IStorage{private static readonly List<DiaryItemDto> Items = new List<DiaryItemDto>();public DiaryItemDto GetById(Guid id){return Items.FirstOrDefault(a => a.Id == id);}public void Add(DiaryItemDto item){Items.Add(item);}public void Delete(Guid id){Items.RemoveAll(i => i.Id == id);}public List<DiaryItemDto> GetItems(){return Items;}}