我一直在学习
存储库
和
工作单位
来自各种来源的模式,包括以下内容:
http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/implementing-the-repository-and-unit-of-work-patterns-in-an-asp-net-mvc-application
如果您浏览到上面的链接
创建工作单元类
存在以下情况:
private GenericRepository<Department> departmentRepository;
private GenericRepository<Course> courseRepository;
这很好,但我想尝试扩展Generic的工作单元类,并设置一个GenericRepository集合,这样我就可以根据我通过的模型动态更新。
我最终想在我的
控制器
以下为:
public class LedgerUserController : Controller
{
private GenericUnitOfWork unitOfWork = new GenericUnitOfWork();
LedgerUser ledgeruser = new LedgerUser();
public ActionResult Index()
{
//var ledgerusers = db.LedgerUsers.Include(l => l.Image).Include(l => l.UserType);
var view = unitOfWork.Repository(ledgeruser).Get(l => l.LastName == "smith");
return View(view.ToList());
}
}
到目前为止,我的类和接口如下:
I存储.cs
/// <summary>
/// Generic Repository for CRUD Operations and methods
/// to locate entities within your store. This is not specific to which Data Access
/// tools your are using (Direct SQL, EF, NHibernate, etc).
/// </summary>
public interface IRepository<T> where T : class
{
//--Search Operations
IQueryable<T> GetAll();
IEnumerable<T> GetAllList();
IEnumerable<T> Get(Expression<Func<T,bool>> filter);
T GetIt(Expression<Func<T, bool>> filter);
T GetById(object id);
//--CRUD Operations
void Create(T entity);
void Update(T entity);
void Delete(T entity);
}
通用存储库.cs
///
///用于查找实体的存储库类
///CRUD操作
///
///
公共类GenericRepository:
I存放处,其中TEntity:class
{
internal AccountsContext context;
internal DbSet<TEntity> dbSet;
internal IQueryable<TEntity> query;
/// <summary>
/// Default Constructor.
/// </summary>
/// <param name="context"></param>
public GenericRepository(AccountsContext context)
{
this.context = context;
this.dbSet = context.Set<TEntity>();
}
#region Methods
#region Search Functionality
/// <summary>
/// Obtain the whole Entity to query if needed.
/// </summary>
/// <returns>IQueryable object.</returns>
public virtual IQueryable<TEntity> GetAll()
{
IQueryable<TEntity> query = dbSet;
return query;
}
/// <summary>
/// Obtain the whole Entity to Enumerate throught if needed.
/// </summary>
/// <returns>IEnumerble object.</returns>
public virtual IEnumerable<TEntity> GetAllList()
{
IQueryable<TEntity> query = dbSet;
return query.ToList();
}
/// <summary>
/// Locate an Entity by its indexed id.
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
public virtual TEntity GetById(object id)
{
return dbSet.Find(id);
}
/// <summary>
/// Gets a collection based on LINQ lambda expressions
/// </summary>
/// <param name="filter">Lambda Expression</param>
/// <returns>Query</returns>
public virtual IEnumerable<TEntity> Get(Expression<Func<TEntity, bool>> filter)
{
query = dbSet;
if (filter != null)
{
query = query.Where(filter);
}
return this.query.ToList();
}
/// <summary>
/// Gets one record based on a one-to-one relationship.
/// </summary>
/// <param name="filter">Lambda Expression.</param>
/// <returns>One record.</returns>
public virtual TEntity GetIt(Expression<Func<TEntity, bool>> filter)
{
IQueryable<TEntity> query = dbSet;
return query.SingleOrDefault(filter);
}
#endregion
#region CRUD Functionality
/// <summary>
/// Used to create a new entity into the database.
/// </summary>
/// <param name="entity">Entity to create.</param>
public virtual void Create(TEntity entity)
{
dbSet.Add(entity);
}
/// <summary>
/// Used to update an entity that already exists in the
/// database.
/// </summary>
/// <param name="entity">Entity to update.</param>
public virtual void Update(TEntity entity)
{
dbSet.Attach(entity);
context.Entry(entity).State = EntityState.Modified;
}
/// <summary>
/// Used to delete an entity from the database.
/// </summary>
/// <param name="entity">Entity to delete.</param>
public virtual void Delete(TEntity entity)
{
if (context.Entry(entity).State == EntityState.Detached)
{
dbSet.Attach(entity);
}
dbSet.Remove(entity);
}
#endregion
#endregion
}
#endregion
通用工作单位.cs
以下为:
/// <summary>
/// Unit of work class that handles multiple Repositories
/// and shares the context.
/// </summary>
public class GenericUnitOfWork : IUnitOfWork
{
private AccountsContext context = new AccountsContext();
Dictionary<string, GenericRepository<IRepository<IRepositoryEntity>>> repostories = null;
/// <summary>
/// Generic Repository method which checks the repository is available if not,
/// it sets it up.
/// </summary>
/// <param name="entity">Entity</param>
/// <returns>Repository to use.</returns>
public GenericRepository<IRepository<IRepositoryEntity>> Repository (IRepositoryEntity entity)
{
string index = entity.GetType().ToString();
if (!repostories.ContainsKey(index))
{
//Reflections to create the repoositiory if it is not needed.
Type type1 = typeof(GenericRepository<>);
Type[] typeArgs = {typeof(IRepositoryEntity)};
Type constructed = type1.MakeGenericType(typeArgs);
object o = Activator.CreateInstance(constructed);
if(o is GenericRepository<IRepository<IRepositoryEntity>>)
{
var rep = (GenericRepository<IRepository<IRepositoryEntity>>)o;
rep.context = this.context;
repostories.Add(index, rep);
}
}
return this.repostories[index];
}
/// <summary>
/// Save method.
/// </summary>
public void Save()
{
context.SaveChanges();
}
private bool disposed = false;
/// <summary>
/// Dispose the conxtext when finished.
/// </summary>
/// <param name="disposing"></param>
protected virtual void Dispose(bool disposing)
{
if (!this.disposed)
{
if (disposing)
{
context.Dispose();
}
}
this.disposed = true;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
}
}
现在我知道Repositorys的实现Dictionary和Repository方法是不正确的(Generic Types是错误的),因为在我的lambda表达式中,它无法解析ledgeruser LastName。
var view = unitOfWork.Repository(ledgeruser).Get(l => l.LastName == "smith");
我是否过度设计了这个问题,或者是否有一种很好的干净的方法来使用我的通用存储库集合创建通用工作单元,这些存储库是基于模型对象给定(例如上面的LedgerUser)设置和创建的。
