Question

我无法弄清楚如何让Unity与我的通用存储库一起工作。这是我的基本设置：

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

返回unitOfWork.CustomerRepository时的错误是：

无法隐式转换类型＆＃39; CustomerRepository＆＃39;到＆＃39;存储库＆＃39;

我完全迷失了，我已经尝试了很多方式来注册它，我开始认为我需要做一些其他事情来实现我想要的东西......不知道我在使用RegisterTypes做了什么这一点，你可以看到：

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>));

这些注册方式都没有帮助。

编辑1：

我怎样才能让它发挥作用？：

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

如果我理解正确，并且在更多行中分解你的代码，那么你就是这样做的：

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

因此，您间接指定CustomerRepository类型的值来键入Repository<IEntity>，这将无效，因为Repository<IEntity>不是CustomerRepository的基本类型。另一方面，类型Repository<Customer>是CustomerRepository的基类，因此将CustomerRepository分配给Repository<Customer>即可。

*编辑*

根据您的意见，提供一些新的见解：

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.");
}

或者......使用反射（较慢）：

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

Unity依赖注入 - 使用通用存储库返回类型的方法

1 个答案: