Question

原谅我，我不擅长EF6。如果我犯了一些错误。请帮我纠正一下。感谢。

首先，我想在我的服务层中实现业务逻辑，如下所示。

public class userService
{
    void createWithCommit(User user)
    {
        MyEntityContext db= new MyEntityContext ();
        ...
        db.Users.add(user);//Add a new user entity
        ....
        Work w = new Work();
        ... 
        db.Works.add(w);//Add a new work entity
        db.savechanges();//commit the changes which will insert 2 new record . one is user . another is work.
    }
}

但在某些服务类中，我想在一个事务中调用多个其他服务方法，如下所示。

class utilService
{
    void update(SomeClass cls)
    {
        using (var tran=new TransactionScope())
        {
          userService userSvr= new userService();
          userSvr.create();//this method already include a savechanges().
          jobService jobSvr= new jobService();
          jobSvr.update();//this method may include another savechanges().
          tran.Complete();//I don't why EF6 doesn't have the Commit method. just has the Complete method.
        }

    }
}

所以我可以在ASP.net MVC控制器中使用它，如下所示。

class SomeController
{
    ActionResult index()
    {
        userService userSvr = new userService();
        userSvr.createWithCommit();

    }

    ActionResult util()
    {
        utilService utilSvr = new utilService ();
        userSvr.update(....);

    }
}

所以你可以看到我的想法是我想将多种服务方法包含在一个事务中。并且每个包含的服务方法可能包含也可能不包含代码SaveChanges()（这意味着提交了一个事务。对吧？）。

你可以看到。在我的测试中，我尝试使用TransactionScope将多种服务方法包含在一个事务中。我的意思是方法utilService.update()。但似乎TransactionScope在SaveChanges() is called之后无效。所以我的问题是：

有没有可能将它作为我的想法来实现？如果有。我应该采用什么样的模式？（我听说过UOW和Repository模式。它们是解决方案吗？谢谢。）

Answer 1

您需要实现工作单元模式以避免交易范围。Unit of Work和Repository Pattern现在使用相当广泛。

UoW公开公共方法Commit来存储更改。

通用存储库

public class GenericRepository<TEntity> where TEntity : class
{
    internal SchoolContext context;
    internal DbSet<TEntity> dbSet;

    public GenericRepository(SchoolContext context)
    {
        this.context = context;
        this.dbSet = context.Set<TEntity>();
    }

    public virtual IEnumerable<TEntity> Get(
        Expression<Func<TEntity, bool>> filter = null,
        Func<IQueryable<TEntity>, IOrderedQueryable<TEntity>> orderBy = null,
        string includeProperties = "")
    {
        IQueryable<TEntity> query = dbSet;

        if (filter != null)
        {
            query = query.Where(filter);
        }

        foreach (var includeProperty in includeProperties.Split
            (new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
        {
            query = query.Include(includeProperty);
        }

        if (orderBy != null)
        {
            return orderBy(query).ToList();
        }
        else
        {
            return query.ToList();
        }
    }

    public virtual TEntity GetByID(object id)
    {
        return dbSet.Find(id);
    }

    public virtual void Insert(TEntity entity)
    {
        dbSet.Add(entity);
    }

    public virtual void Delete(object id)
    {
        TEntity entityToDelete = dbSet.Find(id);
        Delete(entityToDelete);
    }

    public virtual void Delete(TEntity entityToDelete)
    {
        if (context.Entry(entityToDelete).State == EntityState.Detached)
        {
            dbSet.Attach(entityToDelete);
        }
        dbSet.Remove(entityToDelete);
    }

    public virtual void Update(TEntity entityToUpdate)
    {
        dbSet.Attach(entityToUpdate);
        context.Entry(entityToUpdate).State = EntityState.Modified;
    }
}

<强>的UnitOfWork

public class UnitOfWork : IDisposable
{
    //Context Creation in the UnitOfWork
    //This context is supplied to all Repository 
    //Hence One Commit save All Changes
    private SchoolContext context = new SchoolContext();
    private GenericRepository<Department> departmentRepository;
    private GenericRepository<Course> courseRepository;

    public GenericRepository<Department> DepartmentRepository
    {
        get
        {

            if (this.departmentRepository == null)
            {
                this.departmentRepository = new GenericRepository<Department>(context);
            }
            return departmentRepository;
        }
    }

    public GenericRepository<Course> CourseRepository
    {
        get
        {

            if (this.courseRepository == null)
            {
                this.courseRepository = new GenericRepository<Course>(context);
            }
            return courseRepository;
        }
    }

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

    private bool disposed = false;

    protected virtual void Dispose(bool disposing)
    {
        if (!this.disposed)
        {
            if (disposing)
            {
                context.Dispose();
            }
        }
        this.disposed = true;
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }
}

<强>用法

  //Sample Controller
 public class CourseController : Controller
   {
      //Initialize the unit of work here
      private UnitOfWork unitOfWork = new UnitOfWork();

      Public Void MyBussinessTransaction()
      {
         unitOfWork.CourseRepository.Insert(course);
         unitOfWork.DepartmentRepository.Insert(department)
         unitOfWork.Save();
      }
   }

Implementing the Repository and Unit of Work Patterns

Martin Flower explanation of UOW

在一次交易中调用多种服务方法

1 个答案: