列出来自两个不同模型的值

Question

I want to create a foreach that contains List data from two different tables (models), but I have this error message:

Controller:

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using this.Models;
using this.Repositories;
using this.Services;

namespace this.Controllers
{
public class ProductosController : BasicController
{
    //private EfDatabase db = new EfDatabase();
    private readonly ProductosService ProductosService;

    public ProductosController(ProductosService productosService)
    {
        ProductosService = productosService;
    }

    // GET: Productos

    public ActionResult Productos()
    {
        var productos = ProductosService.GetAllProducts();

        var model = new ProductosViewModel
        {
            ProductosListes = productos
        };

        return View(model);

Service:

 using System;
 using System.Collections.Generic;
 using System.Data.Entity;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using this.Models;
 using this.Repositories;

namespace this.Services
{
   public class ProductosService : BaseService
    {

       public ProductosService(Repository repository)
        : base(repository)
    {
    }

 public List<ProductosModel> GetAllProducts()
    {
        var items = Repository.Productos()
            .Include(x => x.Subcategoria)
            .ToList();

        return items;
    }

ViewModel:

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;

namespace this.Models
{
  public class ProductosViewModel
 {

    public List<ProductosModel> ProductosListes { set; get; }

    public List<SubcategoriasModel> SubcategoriasListes { get; set; }


    }
 }

What am I doing wrong?

Help is very appreciated, thanks for reading.

Answer 1

The YSOD is telling you what the problem is: you don't have a default constructor on the controller, and the DefaultControllerFactory wants one.

The minimum required to get your code working is to add the requisite default constructor. You can chain into the overloaded constructor, like so:

public class ProductosController : BasicController
{
    private readonly ProductosService ProductosService;

    public ProductosController()
        : this(new ProductosService())
    {

    }

    public ProductosController(ProductosService productosService)
    {
        ProductosService = productosService;
    }
}

Answer 2

If you are using a DI like Unity, you need to make sure that you are registering your Interface classes to Map with your repositories:

eg: In your Service:

using System;  using System.Collections.Generic;  using System.Data.Entity;  using System.Linq;  using System.Text;  using System.Threading.Tasks;  using DismedHmo.Models;  using DismedHmo.Repositories;

namespace DismedHmo.Services {    public class ProductosService : BaseService, IProductosService
    {

       public ProductosService(Repository repository)
        : base(repository)
    {
    }

 public List<ProductosModel> GetAllProducts()
    {
        var items = Repository.Productos()
            .Include(x => x.Subcategoria)
            .ToList();

        return items;
    }

I would create a IProductosService interface which is what your controller consumes:

   private readonly IProductosService _productosService

   public ProductosController(IProductosService productosService)
    {
        _productosService = productosService;
    }

The main problem you are having is because your BaseService has a constructor, if you remove this constructor then you will be able to have the BaseService nicely be created by the DI.

If you are using something like Unity to do your DI Configuration, you need to register the Mapping between Concrete and Abstract Classes:

public static void RegisterTypes(IUnityContainer container)

            {

                container.RegisterType<IProductosService, ProductosService>(new PerRequestLifetimeManager());
                Synergy5.ComponentConfigure.UnityConfigure.RegisterTypes(container, ()
    => new PerRequestLifetimeManager());

            }

This is because when the Compiler comes across your Controller with a type of ProductosService, it doesnt know how to instantiate it, because there is a constructor on it where it needs to try to push a value in, yet that value is going to be null cause it does not actually know where to get it from.

My rule which seems to work, is that you should always use an interface to get a instance of any of your Repositories or Services, not the Concrete object, as you need to instantiate a concrete object, you don't need to instantiate the constructor of an Abstract class.