Unity依賴注入 - 具有通用存儲庫的方法返回類型

Question

我無法弄清楚如何讓Unity與我的通用存儲庫一起工作。這是我的基本設置：

public static Repository<IEntity> GetRepository() 
{ 
    //This is of type CustomerRepository 
    return unitOfWork.CustomerRepository;   
} 


CustomerRepository : Repository<Customer>, ICustomerRepository 
Repository<TEntity> : IRepository<TEntity> where TEntity : class, IEntity 

ICustomerRepository : IRepository<Customer> 
IRepository<TEntity> : IDisposable where TEntity : class, IEntity 

Customer : IEntity 

在返回unitOfWork.CustomerRepository的錯誤是：

不能鍵入 'CustomerRepository' 隱式轉換爲 '資源庫'

完全迷路了，我已經嘗試了很多註冊方法，以至於我開始認爲我需要做其他事情來實現我想要的功能......在這一點上，我不知道我在使用RegisterType進行的操作，如您所見：

container.RegisterType<IEntity, Customer>(); 
container.RegisterType(typeof(Repository<Customer>), typeof(CustomerRepository)); 
container.RegisterType(typeof(CustomerRepository), typeof(Repository<Customer>)); 

container.RegisterType(typeof(Repository<IEntity>), typeof(Repository<Customer>)); 
container.RegisterType(typeof(Repository<Customer>), typeof(Repository<IEntity>)); 


container.RegisterType(typeof(Repository<>), typeof(Repository<IEntity>)); 
container.RegisterType(typeof(Repository<IEntity>), typeof(Repository<>)); 

      //--------- 

container.RegisterType(typeof(IRepository<Customer>), typeof(Repository<IEntity>)); 
container.RegisterType<IRepository<Customer>, CustomerRepository>(); 
container.RegisterType(typeof(Repository<IEntity>), typeof(CustomerRepository)); 


      //-------------------- 
container.RegisterType(typeof(IRepository<>), typeof(Repository<>)); 
container.RegisterType<ICustomerRepository, CustomerRepository>(); 

container.RegisterType<IRepository<Customer>, ICustomerRepository>(); 
container.RegisterType<Repository<Customer>, CustomerRepository>(); 
container.RegisterType<IRepository<Customer>, CustomerRepository>(); 

container.RegisterType<IRepository<Customer>, ICustomerRepository>(); 
container.RegisterType<Repository<Customer>, CustomerRepository>(); 
container.RegisterType<IRepository<Customer>, CustomerRepository>(); 

container.RegisterType(typeof(IRepository<IEntity>), typeof(IRepository<Customer>)); 

沒有任何註冊它的方法正在幫助。

編輯1：

我怎樣才能得到這個工作？：

public static Repository<TEntity> GetRepository<TEntity>(string entityName, string conectionName) where TEntity : class, IEntity 
{ 
    var unitOfWork = new UnitOfWork(connectionName); 

    switch(entityName){ 
    case "Customer": 
      return unitOfWork.CustomerRepository; 
    } 

    return null; 
} 

Answer 1

如果我理解正確，並打破在多行代碼，你這樣做：

public static Repository<IEntity> GetRepository() 
{ 
    CustomerRepository repository1 = unitOfWork.CustomerRepository; 
    Repository<IEntity> repository2 = repository1; 
    return repository2; 
} 

因此，間接地，您將類型CustomerRepository的值賦值爲Repository<IEntity>，這將不起作用，因爲Repository<IEntity>不是基本類型CustomerRepository。另一方面，類型Repository<Customer>是CustomerRepository的基類，因此將CustomerRepository指定給Repository<Customer>將起作用。

*編輯*

根據您的意見，一些新的見解：

public static Repository<TEntity> GetRepository<TEntity>() 
    where TEntity : class, IEntity 
{ 
    if (typeof(TEntity) == typeof(Customer)) 
     return (Repository<TEntity>)(object)new Repository<Customer>(); 
    if (typeof(TEntity) == typeof(Product)) 
     return (Repository<TEntity>)(object)new Repository<Product>(); 
    throw new Exception("Entity of type " + typeof(IEntity).Name + " is not supported."); 
} 

還是......使用反射（慢）：

public static Repository<TEntity> GetRepository<TEntity>() 
    where TEntity : class, IEntity 
{ 
    Type repositoryType = typeof(Repository<>).MakeGenericType(typeof(TEntity)); 
    return (Repository<TEntity>)Activator.CreateInstance(repositoryType); 
}