System.InvalidOperationException: Unable to allow service for type

Question

I am working on a web API with an ASP.NET core. When I execute my API with a mail request, an exception is thrown before my breakpoint in the Post UnitController method.

Exception

Request to start HTTP / 1.1 POST http: // localhost: 5000 / api / unit application / json 31 fail: Microsoft.AspNetCore.Server.Kestrel [13] Connection identifier "0HKVTL9A1LTD4": an unhandled exception was thrown by the application. System.InvalidOperationException: Cannot resolve the service for type "Project.DataAccess.Repository.UnitRepository" when trying to activate "Project.Service.UnitService".

Context

namespace Project.DataAccess.Library.Interface { public interface IBaseRepository<M> where M : class, IEntity { IEnumerable<M> SelectAll(); M SelectByID(int id); void Insert(M obj); void Update(M obj); void Delete(int id); void Save(); } } namespace Project.DataAccess.Library { public abstract class BaseRepository<M> : IBaseRepository<M> where M : class, IEntity { protected ProjectContext Db { get; } private DbSet<M> table = null; protected DbSet<M> Table { get { return this.table; } } public BaseRepository(ProjectContext dbContext) { Db = dbContext; this.table = Db.Set<M>(); } public void Delete(int id) { M existing = this.SelectByID(id); if (existing != null) this.table.Remove(existing); } // others methods } } namespace Project.DataAccess.Repository { public class UnitRepository : BaseRepository<Unit>, IUnitRepository { public UnitRepository(Projectcontext) : base(context) { } } } namespace Project.Service { public class UnitService : BaseService<Unit>, IUnitService { public UnitService(UnitRepository unitRepository) : base(unitRepository) { } } } namespace AssoManager.Service.Library { public abstract class BaseService<M> : IBaseService<M> where M : class, IEntity { private IBaseRepository<M> _repository; public BaseService(IBaseRepository<M> repository) { _repository = repository; } public IEnumerable<M> GetAll() { return this._repository.SelectAll(); } } } namespace Project { public class Startup { public Startup(IHostingEnvironment env) { var builder = new ConfigurationBuilder() .SetBasePath(env.ContentRootPath) .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true) .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true) .AddEnvironmentVariables(); Configuration = builder.Build(); } public IConfigurationRoot Configuration { get; } // This method gets called by the runtime. Use this method to add services to the container. public void ConfigureServices(IServiceCollection services) { // Add framework services. services.AddMvc(); this.DataAccessMySqlConfiguration(services); this.ConfigureRepository(services); this.ConfigureServicesUnit(services); this.ConfigureServicesUser(services); } // This method gets called by the runtime. Use this method to configure the HTTP request pipeline. public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory) { loggerFactory.AddConsole(Configuration.GetSection("Logging")); loggerFactory.AddDebug(); app.UseMvc(); } #region Database configuration public void DataAccessMySqlConfiguration(IServiceCollection services) { services.AddDbContext<ProjectContext>(options => options.UseMySQL(Configuration.GetConnectionString("MsSQLConnection"))); } #endregion #region DataAccess configuration public void ConfigureRepository(IServiceCollection services) { services.AddScoped<IUnitRepository, UnitRepository>(); services.AddScoped<IUserRepository, UserRepository>(); } #endregion #region Services configuration /// <summary> /// Is used to add unit services to the container /// </summary> public void ConfigureServicesUnit(IServiceCollection services) { services.AddTransient<IUnitService, UnitService>(); services.AddTransient<IMeetingService, MeetingService>(); } /// <summary> /// Is used to add user services to the container /// </summary> public void ConfigureServicesUser(IServiceCollection services) { services.AddTransient<IUserService, UserService>(); } #endregion Services configuration } } namespace Project.Controllers { [Route("api/[controller]")] public class UnitController : Controller { private IUnitService UnitService; public UnitController(IUnitService unitService) { UnitService = unitService; } // GET api/units [HttpGet] public IEnumerable<Unit> Get() { return UnitService.GetAll(); } // GET api/unit/5 [HttpGet("{id}")] public IActionResult Get(int id) { Unit unit; //->Check if (id < 1) return BadRequest(); //->Processing unit = UnitService.GetByID(id); if (unit == null) return NotFound(); return new ObjectResult(unit); } // POST api/unit [HttpPost] public IActionResult Post([FromBody]Unit unit) { //->Check if (unit == null) return BadRequest(); //->Processing UnitService.Create(unit); return CreatedAtRoute("Get", new { id = unit.Id }, unit); } // PUT api/unit/5 [HttpPut("{id}")] public void Put(int id, [FromBody]string value) { } // DELETE api/unit/5 [HttpDelete("{id}")] public void Delete(int id) { } } } 

Version

 "dependencies": { "Microsoft.NETCore.App": { "version": "1.0.0", "type": "platform" }, "Microsoft.AspNetCore.Mvc": "1.0.0", "Microsoft.AspNetCore.Server.Kestrel": "1.0.0", "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0", "Microsoft.Extensions.Configuration.FileExtensions": "1.0.0", "Microsoft.Extensions.Configuration.Json": "1.0.0", "Microsoft.Extensions.Logging": "1.0.0", "Microsoft.Extensions.Logging.Console": "1.0.0", "Microsoft.Extensions.Logging.Debug": "1.0.0", "Microsoft.Extensions.Options.ConfigurationExtensions": "1.0.0", "Microsoft.EntityFrameworkCore": "1.0.0", "MySql.Data.Core": "7.0.4-IR-191", "MySql.Data.EntityFrameworkCore": "7.0.4-IR-191", "IdentityServer4": "1.0.0-rc2", "AssoManager.Domain": "1.0.0-*", "AssoManager.Service": "1.0.0-*", "AssoManager.DataAccess": "1.0.0-*" }, 

Question

I think the problem may be related to the inheritance between BaseRepository and IBaseRepository. But I don’t understand where my mistake could be. How can I fix this error?

Thanks for the help:),

Answer 1

You register UnitRepository as IUnitRepository, but request an IoC UnitRepository solution. He has no registration for this, therefore it does not work.

Try making UnitService instead of IUnitRepository, and not UnitRepository, which should allow things (pardon a pun).