ASP.NET Web API und Autofac IoC. Fehler: ExceptionMessage = Kein Konstruktor gefunden

Question

Ich versuche, Autofac für IoC für mein Asp.Net WebApi-Projekt zu verwenden. Ich versuche, eine einfache POST-Anfrage an die API zu senden, aber ohne Erfolg. Ich bin seit einiger Zeit daran fest und kann es nicht herausfinden.

Bitte den entsprechenden Code beachten und entsprechend beraten. Ihre Hilfe würde sehr geschätzt werden.

public interface IEntityRepository<T> where T : class, new() 
{ 
    IQueryable<T> All { get; } 
    IQueryable<T> AllIncluding(params Expression<Func<T,object>>[] includeProperties); 
    IQueryable<T> GetAll(); 
    //IQueryable<T> GetSingle(string entitiesID); 
    IQueryable<T> FindBy(Expression<Func<T, bool>> predicate); 
    void Add(T entity); 
    void Delete(T entity); 
    void Edit(T entity); 
    void Save(); 

    PaginatedList<T> Paginate<TKey>(int pageindex, int pagesize, Expression<Func<T, TKey>> keySelector); 

    PaginatedList<T> Paginate<TKey>(
     int pageindex, int pagesize, 
     Expression<Func<T, TKey>> keySelector, 
     Expression<Func<T, bool>> predicate, 
     params Expression<Func<T, object>>[] includeProperties); 
} 

public class EntityRepository<T> : IEntityRepository<T> where T : class, new() 
{ 
    readonly CirclesDBEntities _entitiesContext; 

    public EntityRepository(CirclesDBEntities entitiesContext) 
    { 
     if (entitiesContext == null) 
     { 
      throw new ArgumentNullException("entitiesContext"); 
     } 
     _entitiesContext = entitiesContext; 
    } 

    public virtual IQueryable<T> GetAll() 
    { 
     return _entitiesContext.Set<T>(); 
    } 

    public IQueryable<T> All 
    { 
     get { return GetAll(); } 
    } 

    public virtual IQueryable<T> AllIncluding(params Expression<Func<T, object>>[] includeProperties) 
    { 
     IQueryable<T> query = _entitiesContext.Set<T>(); 
     foreach (var includeProperty in includeProperties) 
     { 
      query = query.Include(includeProperty); 
     } 
     return query; 
    } 

    public virtual IQueryable<T> FindBy(Expression<Func<T, bool>> predicate) 
    { 
     return _entitiesContext.Set<T>().Where(predicate); 
    } 

    public virtual PaginatedList<T> Paginate<TKey>(int pageIndex, int pageSize, Expression<Func<T, TKey>> keySelector) 
    { 
     return Paginate(pageIndex, pageSize, keySelector, null); 
    } 
    public virtual PaginatedList<T> Paginate<TKey>(
     int pageIndex, int pageSize, 
     Expression<Func<T, TKey>> keySelector, 
     Expression<Func<T, bool>> predicate, 
     params Expression<Func<T, object>>[] includeProperties) 
    { 
     IQueryable<T> query = AllIncluding(includeProperties).OrderBy(keySelector); 
     query = (predicate == null) ? query : query.Where(predicate); 

     return query.ToPaginatedList(pageIndex, pageSize); 
    } 

    public virtual void Add(T entity) 
    { 
     DbEntityEntry dbEntityEntry = _entitiesContext.Entry<T>(entity); 
     _entitiesContext.Set<T>().Add(entity); 
    } 

    public virtual void Edit(T entity) 
    { 
     DbEntityEntry dbEntityEntry = _entitiesContext.Entry<T>(entity); 
     dbEntityEntry.State = EntityState.Modified; 
    } 

    public virtual void Delete(T entity) 
    { 
     DbEntityEntry dbEntityEntry = _entitiesContext.Entry<T>(entity); 
     dbEntityEntry.State = EntityState.Deleted; 
    } 

    public virtual void Save() 
    { 
     _entitiesContext.SaveChanges(); 
    } 
} 

public static class TermRepository 
{ 
    public static Term GetCurrentTerm(this IEntityRepository<Term> termRepository) 
    { 
     return termRepository.GetAll().OrderByDescending(x => x.DateUploaded).FirstOrDefault(); //descending puts the most recent item on top of the stack 
    } 
} 

public class TermsService : ITermsService 
{ 
    private readonly IEntityRepository<Term> _termRepository; 

    public TermsService(IEntityRepository<Term> termRepository) 
    { 
     _termRepository = termRepository; 
    } 

    public Term GetMostRecentTerm() 
    { 
     Term term = _termRepository.GetCurrentTerm(); 
     return term; 
    } 

    public bool UploadNewTerm(string newTerm) 
    { 
     Term term = new Term(); 
     term.TermID = SetAccountID(); 
     term.Term1 = newTerm; 
     term.DateUploaded = DateTime.Now; 

     _termRepository.Add(term); 
     _termRepository.Save(); 

     return true; 
    } 

} 

public interface ITermsService 
{ 
    Term GetMostRecentTerm(); 
    bool UploadNewTerm(string Term); 
} 

public static class AutofacConfig 
{ 
    public static void Initialize(HttpConfiguration config) 
    { 
     Initialize(config, 
     RegisterServices(new ContainerBuilder())); 
    } 
    public static void Initialize(HttpConfiguration config, IContainer container) 
    { 
     config.DependencyResolver = new AutofacWebApiDependencyResolver(container); 
    } 
    private static IContainer RegisterServices(ContainerBuilder builder) 
    { 
     builder.RegisterApiControllers(Assembly.GetExecutingAssembly()); 


     // registration goes here 


     //EF DbContext 
     builder.RegisterType<CirclesDBEntities>() 
      .As<DbContext>() 
      .InstancePerRequest(); 

     //Repositories       
     builder.RegisterGeneric(typeof(EntityRepository<>)) 
      .As(typeof(IEntityRepository<>)) 
      .InstancePerDependency(); 

     //this makes it check non-public classes 
     //builder.RegisterGeneric(typeof(EntityRepository<>)) 
      //.As(typeof(IEntityRepository<>)) 
      //.InstancePerRequest().FindConstructorsWith(
       //new DefaultConstructorFinder(type => 
        //type.GetConstructors(BindingFlags.NonPublic | BindingFlags.Instance))) 
      //.As(typeof(IEntityRepository<>)); 


     //Services 
     builder.RegisterType<TermsService>() 
      .As<ITermsService>() 
      .InstancePerRequest(); 


     return builder.Build(); 
    } 
} 

public class WebApiApplication : System.Web.HttpApplication 
{ 
    protected void Application_Start() 
    { 
     //Registering routes from the WebApi.Config file 
     GlobalConfiguration.Configure(Config.WebApiConfig.Register); 

     //Registering routes from the HelpPageAreaRegistration in the areas section 
     GlobalConfiguration.Configure(CirclesWebApi.Areas.HelpPage.HelpPageAreaRegistration.RegisterAllAreas); 


     GlobalConfiguration.Configure(Config.AutofacConfig.Initialize); 


    } 
} 

public class TermsController : ApiController 
{ 
    public readonly ITermsService _termService; 

    public TermsController(ITermsService termService) 
    { 
     _termService = termService; 
    } 

    [HttpPost] 
    public HttpResponseMessage PostTerms() 
    { 
     string terms = "terms this is a new term inserted through fiddler"; 

     if(terms != null) 
     { 
      bool created = _termService.UploadNewTerm(terms); 

      if (created) 
      { 
       var response = Request.CreateResponse(HttpStatusCode.Created); 
       return response; 
      } 
      else 
       return Request.CreateResponse(HttpStatusCode.InternalServerError); 
     } 
     else 
     { 
      return Request.CreateResponse(HttpStatusCode.BadRequest); 
     } 
    } 
} 

Fehler:

ExceptionMessage=None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' 

Answer 1

Im Konstruktor von EntityRepository<T> Sie CirclesDBEntities injizieren, aber Sie es als DbContext registrieren. Sie können dies beheben, indem Sie dem Konstruktor DbContext injizieren, indem Sie Ihre Registrierung ändern, indem Sie .As<DbContext>() Teil Ihrer Registrierung entfernen oder .AsSelf() zu Ihrer Registrierung hinzufügen.