Asp.net 核心中的条件依赖解析

Question

我有一个 2 控制器 PayerController 和 BusinessController。 两个 Controller 构造函数都将 EntityManager 作为参数，这是一个抽象类。 我想根据我使用的控制器解析每个 Manager 类。

对于 PayerController，我想注入 PayerManager 类，对于 BusinessController，我想注入 BusinessManager。

目前，我正在获取已使用 EntityManager 解决的最后一个对象，即 BusinessManager。

我记得在 Ninject 中，我们可以很容易地进行条件注入。

这就是我解决依赖项的当前方式，但无法正常工作。

启动文件

services.AddScoped(typeof(EntityManager), typeof(PayerManager));
services.AddScoped(typeof(EntityManager), typeof(BusinessManager));

控制器

public class PayerController
{
   private PayerManager Manager{get;}
   public PayerController(EntityManager entityManager)
   {
      Manager = entityManager as PayerManager;
   }
}

经理班

public class PayerManager : EntityManager
{
    public void MyPayer()
    {
    }  
}

public class BusinessManager : EntityManager
{
    public void MyBusiness()
    {
    }
}

public abstract class EntityManager
{
    public string IAMCommon()
    {
        return "";
    }
}

Answer 1

我不明白为什么您认为在这种情况下需要条件依赖注入，因为使其工作的解决方案非常简单。

您可以更改控制器以注入他们需要的正确类型的依赖项。

public class PayerController
{
   private PayerManager Manager { get; }

   public PayerController(PayerManager manager)
   {
      Manager = manager;
   }
}

public class BusinessController
{
   private BusinessManager Manager { get; }

   public BusinessController(BusinessManager manager)
   {
      Manager = manager;
   }
}

然后确保这两种类型都在服务容器中注册。

services.AddScoped<PayerManager>();
services.AddScoped<BusinessManager>();

更新

更好的方法是使用接口和可能的抽象通用控制器。

定义你的接口：

public interface IEntityManager { }
public interface IPayerManager : IEntityManager { }
public interface IBusinessManager : IEntityManager { }

更新您的类以实现接口：

public abstract class EntityManager : IEntityManager 
{ 
    protected EntityManager() { }
}

public class PayerManager : EntityManager, IPayerManager 
{ 
    public PayerManager() : base() { }
}

public class BusinessManager : EntityManager, IBusinessManager 
{ 
    public BusinessManager() : base() { }
}

然后创建一个基本控制器类：

public abstract class EntityController<T> : Controller where T : class, IEntityManager
{
    protected(T manager)
    {
        Manager = manager
    }

    protected T Manager { get; }
}

更改您的控制器以从基本控制器继承：

public class PayerController : EntityController<IPayerManager>
{
   public PayerController(IPayerManager manager) : base(manager) { }
}

public class BusinessController : EntityController<IBusinessManager>
{
   public BusinessController(IBusinessManager manager) : base(manager) { }
}

并更新服务寄存器：

services.AddScoped<IPayerManager, PayerManager>();
services.AddScoped<IBusinessManager, BusinessManager>();

Answer 2

为控制器中的每个具体类和注入接口制作接口

启动文件

services.AddScoped<IPayerManager, PayerManager>();
services.AddScoped<IBusinessManager, BusinessManager>();

控制器

public class PayerController
{
    private IPayerManager _entityManager{get;}
    public PayerController(IPayerManager entityManager)
   {
       _entityManager= entityManager;
   }
}


public class BusinessController
{
    private IBusinessManager _entityManager{get;}
    public BusinessController(IBusinessManager entityManager)
   {
       _entityManager= entityManager;
   }
}

经理班

public class PayerManager : EntityManager,IPayerManager 
{
    public void MyPayer()
    {
    }
}

 public class BusinessManager : EntityManager,IBusinessManager 
 {
     public void MyBusiness()
     {
     }
 }

 public abstract class EntityManager
 {
     public string IAMCommon()
     {
         return "";
     }
 }

接口

public interface IPayerManager
{
    void MyPayer();
}

public interface IBusinessManager
{
    void MyBusiness();
}

Answer 3

@Maxspan，我的建议：

将所有接口放在 Contracts 文件夹中，并将此文件夹放在 Models/Entities 文件夹中（Models/Entities 文件夹 - Contracts 文件夹）

实体管理器接口

namespace WebApplication1.Entities.Contracts
{
    public interface IEntityManager
    {
        //Method signature only
        string IAMCommon();
    }
}

商务管理界面

namespace WebApplication1.Entities.Contracts
{
    public interface IBusinessManager : IEntityManager
    {
        //Method signature only
        void MyBusiness();
    }
}

IPayerManager 接口

namespace WebApplication1.Entities.Contracts
{
    public interface IPayerManager : IEntityManager
    {
        //Method signature only
        void MyPayer();
    }
}

BusinessManager 具体类

using System;
using WebApplication1.Entities.Contracts;

namespace WebApplication1.Entities
{
    public class BusinessManager : IBusinessManager
    {
        //Method signature in IEntityManager
        public string IAMCommon()  //Heritage in IBusinessManager (IBusinessManager : IEntityManager)
        {
            //Implement your code here.
            throw new NotImplementedException();
        }

        //Method signature in IBusinessManager
        public void MyBusiness() 
        {
            //Implement your code here.
            throw new NotImplementedException();
        }
    }
}

PayerManager 具体类

using System;
using WebApplication1.Entities.Contracts;

namespace WebApplication1.Entities
{
    public class PayerManager : IPayerManager
    {
        //Method signature in IEntityManager
        public string IAMCommon() //Heritage in IPayerManager (IPayerManager : IEntityManager)
        {
            //Implement your code here.
            throw new NotImplementedException();
        }

        //Method signature in IPayerManager
        public void MyPayer()
        {
            //Implement your code here.
            throw new NotImplementedException();
        }
    }
}

创业班

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using WebApplication1.Entities;
using WebApplication1.Entities.Contracts;

namespace WebApplication1
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddScoped<IBusinessManager, BusinessManager>();
            services.AddScoped<IPayerManager, PayerManager>();
        }
    }
}

业务控制器

using Microsoft.AspNetCore.Mvc;
using WebApplication1.Entities.Contracts;

namespace WebApplication1.Controllers
{
    public class BusinessController : Controller
    {
        private readonly IBusinessManager _businessManager;

        public BusinessController(IBusinessManager businessManager)
        {
            _businessManager = businessManager;
        }

        public IActionResult Index()
        {
            //Both methods in BusinessManager due to heritage (BusinessManager : IBusinessManager)
            _businessManager.IAMCommon(); 
            _businessManager.MyBusiness();

            return View();
        }
    }
}

付款人控制器

using Microsoft.AspNetCore.Mvc;
using WebApplication1.Entities.Contracts;

namespace WebApplication1.Controllers
{
    public class PayerController : Controller
    {
        private readonly IPayerManager _payerManager;

        public PayerController(IPayerManager payerManager)
        {
            _payerManager = payerManager;
        }

        public IActionResult Index()
        {
            //Both methods in PayerManager due to heritage (PayerManager : IPayerManager)
            _payerManager.IAMCommon(); 
            _payerManager.MyPayer(); 

            return View();
        }
    }
}