存儲庫模式的通用接口繼承和類實現

Question

我已經閱讀了一些關於約束的內容，並嘗試在我的存儲庫模式中實現它。

我想要類似下面的東西，但不能完全得到它編譯。

 public interface IRepository<T>
 {
    void GetAllData<T>();
 }

 //This needs to inherit from IRepository
 //T has to be a model class
 //V has to be a class that implements IEmployeeRepo
 public interface IEmployeeRepo<T, V> where V : EmployeeRepo where T : class : IRepository<T>
 {
    void DoSomethingEmployeeRelated();
 }

 //Dont think this inheritance is correct
 public class EmployeeRepo<Employee, this> : IEmployeeRepo
 {


 }

 //My example model class
 public class Employee
 {
     public string Name {get;set;}
 }

Answer 1

不確定為什么在存儲庫中有兩個類型參數 - 重點是什么？

* 以下是使用泛型的.NET存儲庫的經典示例：*

* 首先，存儲庫接口：*

public interface IRepository<T> where T : class
{
   T FindSingle(Expression<Func<T,bool>> predicate);
   IQueryable<T> FindAll(); // optional - matter of preference
   void Add(T entity);
   void Remove(T entity);
}

* 其次，通用存儲庫實現（以EF為例）：*

public abstract class GenericRepository<T> : IRepository<T>
{
   private IObjectSet<T> _ObjectSet; // get this in via DI (for example)

   public T FindSingle(Expression<T,bool>> predicate)
   {
      return _ObjectSet.SingleOrDefault(predicate);
   }

   // you can figure out how to do the other implementation methods
}

* 然后，特定存儲庫（每個聚合根應該有一個，每個特定存儲庫的接口也詳細說明特定方法）：*

public EmployeeRepository : GenericRepository<Employee>, IRepository<Employee>
{
   // all regular methods (Find, Add, Remove) inherited - make use of them
   public Employee FindEmployeeByName(string name)
   {
      return FindAll().SingleOrDefault(x => x.Name == name);
      // or you could do: return FindSingle(x => x.Name == name);    
   }
}

用法：

IRepository<Employee> repository = new EmployeeRepository<Employee>();

不要因為泛型而過於瘋狂 - 你需要的唯一一個就是限制存儲庫被封裝在存儲庫后面的實體使用。

我只是使用where T : class 。

其他用於where T : IDomainAggregate或類似的，用於對實際允許的實體類型設置約束。

Answer 2

在這種情況下，我通常有一個實現IRepository <>的基礎repo類，並輸入到基礎Model類。

public interface IRepository<T> where T : IModel
 {
    void GetAll<T>();
    void GetById<T>(int id);
 }    

 public interface IEmployeeRepo<T> : IRepository<T> where T : IModel
 {
    void DoSomethingEmployeeRelated();
 }

 public class BaseRepo : IRepository<T> where T : IModel
 {

    public void GetAll<T>()
    {

    }

    public void GetById<T>(int id)
    {

    }
 }


 public class EmployeeRepo : BaseRepo<Employee>,  IEmployeeRepo<Employee>
 {
    public void DoSomethingEmployeeRelated()
    {

    }

 }

 //My example model class
 public class Employee : IModel
 {
     public int Id {get;set;}
     public string Name {get;set;}
 }

Answer 3

試試這個;

public interface IRepository<T>
 {
    void GetAllData<T>();
 }

 //This needs to inherit from IRepository
 //T has to be a model class
 //V has to be a class that implements IEmployeeRepo
 public interface IEmployeeRepo<T, V> : IRepository<T> where V : EmployeeRepo where T : class
 {
    void DoSomethingEmployeeRelated();
 }

 //Dont think this inheritance is correct
 public class EmployeeRepo : IEmployeeRepo<Employee, EmployeeRepo>
 {
    public void DoSomethingEmployeeRelated()
    {

    }

    public void GetAllData<Employee>()
    {

    }
 }

 //My example model class
 public class Employee
 {
     public string Name {get;set;}
 }