我在这里使用正确的工作单元吗?(Entityi框架4 POCO)
-
25-09-2019 - |
题
我找到了一些如何使用 ef4 创建工作单元的示例,我没有使用过 di/ioc,我想让事情变得简单,这是一个示例(90% 的灵感),我认为这没问题,但因为我正在查看从现在开始使用的模式我想最后一次征求意见。
public interface IUnitOfWork
{
void Save();
}
public partial class TemplateEntities : ObjectContext, IUnitOfWork
{
....
public void Save()
{
SaveChanges();
}
}
public interface IUserRepository
{
User GetUser(string username);
string GetUserNameByEmail(string email);
void AddUser(User userToAdd);
void UpdateUser(User userToUpdate);
void DeleteUser(User userToDelete);
//some other
}
public class UserRepository : IUserRepository, IDisposable
{
public TemplateEntities ctx;
public UserRepository(IUnitOfWork unit)
{
ctx = unit as TemplateEntities;
}
public User GetUser(string username)
{
return (from u in ctx.Users
where u.UserName == username
select u).SingleOrDefault();
}
public string GetUserNameByEmail(string email)
{
return (from u in ctx.Users
where u.Email == email
select u.UserName).SingleOrDefault();
}
public void AddUser(User userToAdd)
{
ctx.Users.AddObject(userToAdd);
}
public void UpdateUser(User userToUpdate)
{
ctx.Users.Attach(userToUpdate);
ctx.ObjectStateManager.ChangeObjectState(userToUpdate, System.Data.EntityState.Modified);
}
public void DeleteUser(User userToDelete)
{
ctx.Users.Attach(userToDelete);
ctx.ObjectStateManager.ChangeObjectState(userToDelete, System.Data.EntityState.Deleted);
}
public void Dispose()
{
if (ctx != null)
ctx.Dispose();
}
}
最后
public class BogusMembership : MembershipProvider
{
public MembershipCreateStatus CreateUser(string username, string password, string email, bool autoemail, string fullname)
{
IUnitOfWork ctx = new TemplateEntities();
using (UserRepository rep = new UserRepository(ctx))
{
using (TransactionScope tran = new TransactionScope())
{
if (rep.GetUser(username) != null)
return MembershipCreateStatus.DuplicateUserName;
if (requiresUniqueEmail && !String.IsNullOrEmpty(rep.GetUserNameByEmail(email)))
return MembershipCreateStatus.DuplicateEmail;
User userToCreate = new User
{
UserName = username,
PassWord = EncodePassword(password),
FullName = fullname,
Email = email,
AutoEmail = autoemail
};
try
{
rep.AddUser(userToCreate);
ctx.Save();
tran.Complete();
return MembershipCreateStatus.Success;
}
catch
{
return MembershipCreateStatus.UserRejected;
}
}
}
}
}
摆脱 IUnitOfWork 和 IDisposal 后,CreateUser 看起来像这样:
public MembershipCreateStatus CreateUser(string username, string password, string email, bool autoemail, string fullname)
{
using (TransactionScope tran = new TransactionScope())
{
using (TemplateEntities ctx = new TemplateEntities())
{
UserRepository rep = new UserRepository(ctx);
//OtherRepository rep2 = new OtherRepository(ctx);
if (rep.GetUser(username) != null)
return MembershipCreateStatus.DuplicateUserName;
if (requiresUniqueEmail && !String.IsNullOrEmpty(rep.GetUserNameByEmail(email)))
return MembershipCreateStatus.DuplicateEmail;
User userToCreate = new User
{
UserName = username,
PassWord = EncodePassword(password),
FullName = fullname,
Email = email,
AutoEmail = autoemail
};
try
{
rep.AddUser(userToCreate);
ctx.SaveChanges();
tran.Complete();
return MembershipCreateStatus.Success;
}
catch
{
return MembershipCreateStatus.UserRejected;
}
}
}
}
解决方案
这看起来基本没问题。但有一些建议:
- 您不应该让存储库处置
TemplateEntities
. 。这样做的原因是,当您在一个事务中需要两个存储库时,就会遇到问题。您应该转移处置该物品的责任TemplateEntities
与TransactionScope
; - 这
TransactionScope
应该提升到一个更高的水平。优选地,TemplateEntities
应该在一个实例化TransactionScope
; - 您不必创建
Save
包装器(如果它不包含功能)。如果您指定void SaveChanges()
于IUnitOfWork
界面,这将拾取SaveChanges
的TemplateEntities
; - 就我个人而言,我不会
string GetUserNameByEmail(...)
反而User GetUserByEmail(...)
因为这样也可以满足您的目的,并且您的优势在于,当您以后需要时,您无需使用两种通过电子邮件地址进行搜索的方法。User GetUserByEmail(...)
; - 你可能想考虑制作
ctx
私人的,或者至少是像这样的私人设置者public TemplateEntities Ctx { get; private set; }
; - 您可以使用如下例所示的方法创建一个抽象存储库。从长远来看,这将为您节省大量枯燥的打字工作:
-
public interface IRepository<TEntity>
{
void Delete(TEntity entity);
/* ... */
}
public abstract class AbstractRepository<TEntity> : IRepository<TEntity>
{
public TemplateEntities ctx;
public AbstractRepository(IUnitOfWork unit)
{
ctx = unit as TemplateEntities;
}
protected abstract ObjectSet<TEntity> Entites { get; }
public virtual void Delete(TEntity entity)
{
Entities.Attach(entity);
ctx.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Deleted);
}
/* ... */
}
public interface IUserRepository : IRepository<User>
{
User GetUser(string username);
/* ... */
}
public class UserRepository : AbstractRepository<User>, IUserRepository
{
public UserRepository(IUnitOfWork unit)
: base(unit)
{
}
protected override ObjectSet<User> Entites
{
get { return ctx.Users; }
}
public User GetUser(string username)
{
return (from u in ctx.Users
where u.UserName == username
select u).SingleOrDefault();
}
/* ... */
}
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