问题描述
我计划开发使用ASP.NET MVC实体框架6(code首先/ POCO)的Web应用程序。我也想用通用的存储库和工作模式在单位我的应用程序。这个应用程序连接到两个以上的数据库,这样,我在应用程序中使用多个的DbContext。
I plan to develop a web application using ASP.NET MVC with Entity Framework 6 (Code First / POCO). I also want to use generic Repository and Unit of Work Pattern in my application. This application connects to more than two databases so, I have to use multiple DbContext in the application.
public class ContextOne : DbContext
{
public DbSet<Model_One1>
public DbSet<Model_One2>
}
public class ContextTwo : DbContext
{
public DbSet<Model_Two1>
public DbSet<Model_Two2>
}
public class ContextThree : DbContext
{
public DbSet<Model_Three1>
public DbSet<Model_Three2>
}
public interface IRepository<T> where T : DbContext
{
void Add<T>(T entity) where T : class;
}
public class Repository<T> where T : DbContext
{
void Add<T>(T entity) where T : class
{
//T is DbContext and Model. So confusing
}
}
public interface IUnitOfWork<IRepository>
{
}
public class UnitOfWork<IRepository>
{
//IRepository contains more than one DbContext how can I initiate them here?
}
//in application should look like this
public class BaseController : Controller
{
protected IRepository repository = new .. //here I have no idea with multiple DbContext
}
public class HomeController : BaseController
{
public ActionResult Add(Model_Two2 model)
{
base.repository.Add<Model_Two2>(model)
}
}
如果我把从控制器的IRepository和IUnitOfWork我怎么能知道匹配的情况下?这是什么问题的最佳实践?
If I call the IRepository and IUnitOfWork from Controller how can I know the matching context? What's the best practice of this problem?
推荐答案
我建议你用一个参数的构造函数创建的UnitOfWork模式接受的DbContext -
I would suggest you to create UnitOfWork pattern with a Constructor parameter to accept DbContext -
public class UnitOfWork : IUnitOfWork
{
private readonly IDbContext _context;
private bool _disposed;
private Hashtable _repositories;
public UnitOfWork(IDbContext context)
{
_context = context;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
public void Save()
{
_context.SaveChanges();
}
public virtual void Dispose(bool disposing)
{
if (!_disposed)
if (disposing)
_context.Dispose();
_disposed = true;
}
public IRepository<TEntity> Repository<TEntity>() where TEntity : class
{
if (_repositories == null)
_repositories = new Hashtable();
var type = typeof(TEntity).Name;
if (_repositories.ContainsKey(type)) return (IRepository<TEntity>) _repositories[type];
var repositoryType = typeof (Repository<>);
var repositoryInstance =
Activator.CreateInstance(repositoryType
.MakeGenericType(typeof (TEntity)), _context);
_repositories.Add(type, repositoryInstance);
return (IRepository<TEntity>) _repositories[type];
}
}
其中IDbContext是 -
where IDbContext is -
public interface IDbContext
{
IDbSet<T> Set<T>() where T : class;
int SaveChanges();
void Dispose();
}
和存储库的实现将是 -
And the repository implementation would be -
public class Repository<TEntity> : IRepository<TEntity> where TEntity : class
{
internal IDbContext Context;
internal IDbSet<TEntity> DbSet;
public Repository(IDbContext context)
{
Context = context;
DbSet = context.Set<TEntity>();
}
public virtual TEntity FindById(object id)
{
return DbSet.Find(id);
}
public virtual void Update(TEntity entity)
{
DbSet.Attach(entity);
}
public virtual void Delete(object id)
{
var entity = DbSet.Find(id);
var objectState = entity as IObjectState;
if (objectState != null)
objectState.State = ObjectState.Deleted;
Delete(entity);
}
public virtual void Delete(TEntity entity)
{
DbSet.Attach(entity);
DbSet.Remove(entity);
}
public virtual void Insert(TEntity entity)
{
DbSet.Attach(entity);
}
public virtual List<TEntity> GetAll()
{
return DbSet.ToList();
}
}
通过这种方法,您可以为个人的DbContext创建的UnitOfWork并有特定的逻辑来提交或回滚中的UnitOfWork。
With this approach you can create a UnitOfWork for individual DBContext and you have specific logic to commit or rollback in UnitOfWork.
这篇关于与多的DbContext工作模式库和单位的最佳实践的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!