carloscds

public void ConfigureServices(IServiceCollection services)
{
    services.AddControllers();

    services.AddSingleton<IServico, Servico>();
    services.AddSingleton<ExecutaServico, ExecutaServico>();
}

carloscds

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace InjecaoDependenciaDiretaEF.Models
{
    public class Cliente
    {
        public int Id { get; set; }

carloscds

using InjecaoDependenciaDiretaEF.Models;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace InjecaoDependenciaDiretaEF.Data
{
    public class AplicacaoContext : DbContext

carloscds

 public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();

            services.AddDbContext<AplicacaoContext>(options =>
                options.UseInMemoryDatabase("DBMemory"));

            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
            services.AddScoped<IEnvioEmail, EnvioEmail>();
        }

carloscds

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace InjecaoDependenciaDiretaEF.Services
{
    public interface IEnvioEmail
    {
        string Enviar();

carloscds

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace InjecaoDependenciaDiretaEF.Services
{
    public class EnvioEmail : IEnvioEmail
    {
        public string Enviar() => "Email Enviado";

carloscds

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using InjecaoDependenciaDiretaEF.Data;
using InjecaoDependenciaDiretaEF.Models;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;

carloscds

static void Main(string[] args)
{
   Stopwatch contador = new Stopwatch();
   contador.Start();
   var db = new NorthwindContext();
   var dados = db.Customers;
   
   foreach(var c in dados)
   {

carloscds

public class Contexto : DbContext
{
    public DbSet<Cliente> Cliente { get; set; }
}

carloscds

public class Cliente
{
    public int ID { get; set; }
    public string Nome { get; set; }
    public string Cidade { get; set; }
    public string UF { get; set; }
}