实体框架4 CTP 4/CTP 5通用存储库模式和单元可测试

Question

我正在玩最新的Entity Framework CTP 5版本并构建一个简单的asp.net MVC博客,其中我只有两个表:Post和Comments.这完全是在POCO中完成的,我只需要DbContext部分的帮助,我需要它可以进行单元测试(使用IDbSet？),我需要一个简单/通用的存储库模式来添加,更新,删除,检索.任何帮助表示赞赏.

谢谢.

Answer 1

从DbContext开始,创建一个名为Database.cs的新文件:

Database.cs

public class Database : DbContext
    {

        private IDbSet<Post> _posts;

        public IDbSet<Post> Posts {
            get { return _posts ?? (_posts = DbSet<Post>()); }
        }

        public virtual IDbSet<T> DbSet<T>() where T : class {
            return Set<T>();
        }
        public virtual void Commit() {
            base.SaveChanges();
        }
}

定义IDatabaseFactory并使用DatabaseFactory实现它:

IDatabaseFactory.cs

public interface IDatabaseFactory : IDisposable
    {
        Database Get();
    }

DatabaseFactory.cs

public class DatabaseFactory : Disposable, IDatabaseFactory {
        private Database _database;
        public Database Get() {
            return _database ?? (_database = new Database());
        }
        protected override void DisposeCore() {
            if (_database != null)
                _database.Dispose();
        }
    }

一次性扩展方法:

Disposable.cs

public class Disposable : IDisposable
    {
        private bool isDisposed;

        ~Disposable()
        {
            Dispose(false);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }
        private void Dispose(bool disposing)
        {
            if(!isDisposed && disposing)
            {
                DisposeCore();
            }

            isDisposed = true;
        }

        protected virtual void DisposeCore()
        {
        }
    }

现在我们可以定义我们的IRepository和RepositoryBase

IRepository.cs

public interface IRepository<T> where T : class
{
    void Add(T entity);
    void Delete(T entity);
    void Update(T entity);
    T GetById(long Id);
    IEnumerable<T> All();
    IEnumerable<T> AllReadOnly();
}

RepositoryBase.cs

public abstract class RepositoryBase<T> where T : class
    {
        private Database _database;
        private readonly IDbSet<T> _dbset;
        protected RepositoryBase(IDatabaseFactory databaseFactory)
        {
            DatabaseFactory = databaseFactory;
            _dbset = Database.Set<T>();
        }

        protected IDatabaseFactory DatabaseFactory
        {
            get; private set;
        }

        protected Database Database
        {
            get { return _database ?? (_database = DatabaseFactory.Get()); }
        }
        public virtual void Add(T entity)
        {
            _dbset.Add(entity);
        }

        public virtual void Delete(T entity)
        {
            _dbset.Remove(entity);
        }

        public virtual void Update(T entity)
        {
            _database.Entry(entity).State = EntityState.Modified;
        }
        public virtual T GetById(long id)
        {
            return _dbset.Find(id);
        }

        public virtual IEnumerable<T> All()
        {
            return _dbset.ToList();
        }
        public virtual IEnumerable<T> AllReadOnly()
        {
            return _dbset.AsNoTracking().ToList();
        }
    }

现在您可以创建IPostRepository和PostRepository:

IPostRepository.cs

     public interface IPostRepository : IRepository<Post>
        {
            //Add custom methods here if needed
            Post ByTitle(string title);
        }

PostRepository.cs

    public class PostRepository : RepositoryBase<Post>, IPostRepository
        {
            public PostRepository(IDatabaseFactory databaseFactory) : base(databaseFactory)
            {
            }
            public Post ByTitle(string title) {
                return base.Database.Posts.Single(x => x.Title == title);
            }
        }

最后,UoW:

IUnitOfWork.cs

public interface IUnitOfWork
{
    void Commit();
}

UnitOfWork.cs

private readonly IDatabaseFactory _databaseFactory;
private Database _database;

public UnitOfWork(IDatabaseFactory databaseFactory)
{
    _databaseFactory = databaseFactory;
}

protected Database Database
{
    get { return _database ?? (_database = _databaseFactory.Get()); }
}

public void Commit()
{
    Database.Commit();
}

在您的控制器中使用:

private readonly IPostRepository _postRepository;
private readonly IUnitOfWork_unitOfWork;

        public PostController(IPostRepository postRepository, IUnitOfWork unitOfWork)
        {
            _postRepository = postRepository;
            _unitOfWork = unitOfWork;
        }

        public ActionResult Add(Post post) {
            _postRepository.Add(post);
            _unitOfWork.Commit();
        }

您需要使用像StructureMap这样的IoC容器来完成这项工作.您可以通过NuGet安装结构图,或者如果您使用的是MVC 3,则可以安装StructureMap-MVC NuGet包.(以下链接)

安装包StructureMap.MVC4

Install-Package StructureMap.MVC3

安装包结构图

如果您有任何疑问,请告诉我.希望能帮助到你.

Answer 2

我只是喜欢这篇关于Entity Framework 4 POCO,Repository和Specification Pattern的深入文章

http://huyrua.wordpress.com/2010/07/13/entity-framework-4-poco-repository-and-specification-pattern/