Repository不能作为泛型方法中的类型参数

Question

我最近遇到了一个我以前没有遇到过的关于依赖关系的问题，并查找它并找到了 Ninject。我已按照有关如何使用它的指南进行操作，但已达到我收到的错误和我不理解的错误的地步。我很一般地写下了标题中的错误，但完整的错误如下：

'Error 1 The type 'MyDBFirstAP.Repository.SQLAPRepository' cannot be used as type parameter 'TImplementation' in the generic type or method 'Ninject.Syntax.IBindingToSyntax.To()'. There is no implicit reference conversion from 'MyDBFirstAP.Repository.SQLAPRepository' to 'MyDBFirstAP.Repository.IAPRepository'.'

它出现在这里：

public class NinjectControllerFactory : DefaultControllerFactory{
    private IKernel ninjectKernel;

    public NinjectControllerFactory() {
        ninjectKernel = new StandardKernel();
        AddBindings();
    }
    protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType) {
        return controllerType == null
            ? null
            : (IController)ninjectKernel.Get(controllerType);
    }
    private void AddBindings()
    {
        ninjectKernel.Bind<IAPRepository>().To<SQLAPRepository>(); // On this line
    }
}

我的控制器的开头是：

 public class ClientsController : Controller
    {
        IAPRepository repository;

        // GET: Clients
        public ClientsController(IAPRepository repository) {
            this.repository = repository;
        }

这里是请求的 SQLRepository 代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using MyDBFirstAP.Models;
using MyDBFirstAP.DI;

namespace MyDBFirstAP.Repository {
    public class SQLAPRepository {
        ApplicationDbContext Database = new ApplicationDbContext();

        #region Client
        public IQueryable<Client> GetAllClients() {
            return Database.Clients;
        }    

        public Client GetClientByID(int id) {
            return Database.Clients.FirstOrDefault(c => c.ClientID == id);
        }

        public IQueryable<Client> GetClientByName(string ClientName) {

            return (from clients in Database.Clients
                    where clients.ClientName.Contains(ClientName)
                    select clients);

        }

        public void AddClient(Client client) {
            Database.Clients.Add(client);
            Database.SaveChanges();
        }

        public void UpdateClient(Client client) {
            var tmpClient = Database.Clients.FirstOrDefault(c => c.ClientID == client.ClientID);
            tmpClient.ClientName = client.ClientName;
            tmpClient.ClientAddress = client.ClientAddress;
            Database.SaveChanges();
        }
        public void DeleteClient(Client client) {
            Database.Clients.Remove(client);
            Database.SaveChanges();
        }
#endregion

        #region Supplier
        public IQueryable<Supplier> GetAllSuppliers() {
            return Database.Suppliers;
        }

        public Supplier GetSupplierByID(int id) {
            return Database.Suppliers.FirstOrDefault(s => s.SupplierID == id);
        }

        public IQueryable<Supplier> GetSupplierByName(string SupplierName) {
            return(from suppliers in Database.Suppliers
                       where suppliers.SupplierName.Contains(SupplierName)
                       select suppliers);
        }

        public void AddSupplier(Supplier supplier) {
            Database.Suppliers.Add(supplier);
            Database.SaveChanges();
        }

        public void UpdateSupplier(Supplier supplier) {
            var tmpSupplier = Database.Suppliers.FirstOrDefault(s => s.SupplierID == supplier.SupplierID);
            tmpSupplier.SupplierName = supplier.SupplierName;
            tmpSupplier.SupplierAddress = supplier.SupplierAddress;
            Database.SaveChanges();
        }

        public void DelteSupplier(Supplier supplier) {
            Database.Suppliers.Remove(supplier);
            Database.SaveChanges();
        }
        #endregion

        #region Claim
        public IQueryable<Claim> GetAllClaims() {
            return Database.Claims;
        }

        public Claim GetClaimByID (int id) {
            return Database.Claims.FirstOrDefault(c => c.ClaimID == id);
        }

        public void AddClaim(Claim claim) {
            Database.Claims.Add(claim);
            Database.SaveChanges();
        }
        public void UpdateClaim(Claim claim) {
            var tmpClaim = Database.Claims.FirstOrDefault(c => c.ClaimID == claim.ClaimID);
            tmpClaim.ClaimTotal = claim.ClaimTotal;
            tmpClaim.ClaimWIP = claim.ClaimWIP;
            tmpClaim.FK_ClientID = claim.FK_ClientID;
            tmpClaim.FK_SupplierID = claim.FK_SupplierID;
            Database.SaveChanges();
        }
        public void DeleteClaim(Claim claim) {
            Database.Claims.Remove(claim);
            Database.SaveChanges();
        }
        #endregion
    }
}

有人可以帮我理解这个错误并帮助我修复它吗？谢谢。

Answer 1

SQLAPRepository 必须实现 IAPRepository。

public class SQLAPRepository : IAPRepository
{
     ....
}

Answer 2

正如 Radin 所说，它必须实现 IAPRepository 接口。当您进行依赖注入时，您允许在运行时使用接口的任何实现。对于生产代码，存在显式配置映射或运行时对可用实现的某种询问。

在 NancyFX TinyIoC is used, and it does not require explicit type mapping. For other solutions like Unity 中有一个为许多实现完成的显式类型映射 container.RegisterType<IMyInterface,MyImplementation>();

Repository不能作为泛型方法中的类型参数

Repository cannot be used as a type parameter in the generic type of method

c#

dependency-injection

ninject