asp.net-mvc-3 - 工作单元模式以及 Unity 和通用存储库实现

Question

我正在实施 DI、UnitOfWork 和存储库模式，如下所示：我需要您的专家对此实施的意见，而且我也面临错误。

---

**Business Domain(Class Lib)**
-Contracts
     -IWelcomeService.cs
-Repositories
     -BaseRepository.cs
     -DataRepository.cs
     -IDataRepository.cs

---

**EF project Lib (I have autogenerated code for Existing Oracle DB)**
-MyEntities.cs (This is additional file I have added for IUnitOfWork implementation

---

**MVC3 Project (Left default folders for simplicity)**
-Factories
     - UnityDependencyResolver.cs
UnityContainerSetup.cs

---

这些自定义实现的代码如下

我的实体.cs

public partial class MyEntities : ObjectContext, IUnitOfWork
{
    #region IUnitOfWork Members

    public void Save()
    {
        base.SaveChanges();
    }

    #endregion
}

IWelcomeService.cs

public interface IWelcomeService
{
    string GetMessage();
}

BaseRepository.cs

public class BaseRepository 
{
    protected IUnitOfWork UnitOfWork { get; set; }

    public BaseRepository(IUnitOfWork unitOfWork)
    {
        this.UnitOfWork = unitOfWork;
    }        
}

public interface IUnitOfWork
{
    void Save();
}

数据存储库.cs

public class DataRepository : BaseRepository, IDataRepository
{
    public DataRepository(IUnitOfWork unitOfWork)
        : base(unitOfWork)
    {

    }

    #region IDataRepository Members

    public string ChangeMessage()
    {
        return "Changed by repository";
    }

    #endregion
}

IDataRepository.cs

public interface IDataRepository
{
    string ChangeMessage();
}

UnityDependencyResolver.cs

public class UnityDependencyResolver : IDependencyResolver
{
    IUnityContainer _container;

    public UnityDependencyResolver(IUnityContainer container)
    {
        _container = container;
    }

    #region IDependencyResolver Members

    public object GetService(Type serviceType)
    {
        object instance;

        try
        {
            instance = _container.Resolve(serviceType);

            if (serviceType.IsAbstract || serviceType.IsInterface)
                return null;

            return instance;
        }
        catch (Exception)
        {
            return null;
        }
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        return _container.ResolveAll(serviceType);
    }

    #endregion
}

UnityContainerSetup.cs

public static void Setup()
    {
        var container = new UnityContainer();
        container.RegisterType<IWelcomeService, WelcomeServices>();
        container.RegisterType<IDataRepository, DataRepository>();
        DependencyResolver.SetResolver(new UnityDependencyResolver(container));
    }

HomeController.cs 公共类 HomeController : Controller { private IWelcomeService _service;

    public HomeController(IWelcomeService service)
    {
        _service = service;
    }

    public ActionResult Index()
    {
        ViewBag.Message = _service.GetMessage();

        return View();
    }

    public ActionResult About()
    {
        return View();
    }
}

问题：当我运行应用程序时，出现以下错误：“没有为此对象定义无参数构造函数”

问题：UnitOfWork 何时启动？如何在设置统一容器时注入 IUnitOfWork？

Answer 1

This is WebAPI, not MVC, but should work the same way... See here, for an example... http://www.asp.net/web-api/overview/extensibility/using-the-web-api-dependency-resolver