Question

Visual Studio - Snapshot of Project Structure

Global.asax.cs文件，其中我已放置依赖项并注册webAPI控制器

using Autofac;
using Autofac.Integration.Mvc;
using Autofac.Integration.WebApi;
using StructureMap;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Http;
using System.Web.Mvc;
using System.Web.Optimization;
using System.Web.Routing;
using GeoLocationApi.Services;
using GeoLocationApi.Controllers;
using GeoLocationApi.Models;
using System.Reflection;

namespace GeoLocationApi
{
    public class WebApiApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            GlobalConfiguration.Configure(WebApiConfig.Register);
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);



            var builder = new ContainerBuilder();


            builder.RegisterType<locationService>().InstancePerRequest();
            builder.RegisterApiControllers(typeof(locationController).Assembly);
            builder.RegisterType<locationContext>().As<locationContext>().InstancePerRequest();
            builder.RegisterWebApiFilterProvider(GlobalConfiguration.Configuration);


            var container = builder.Build();
            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
            GlobalConfiguration.Configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);

            builder.RegisterApiControllers(Assembly.GetExecutingAssembly());

        }
    }
}

locationService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using GeoLocationApi.Models;
using System.Linq.Expressions;

namespace GeoLocationApi.Services
{
    public partial class locationService : IlocationService
    {
        private readonly IRepository<location> _locationRepository;

        public locationService(IRepository<location> locationRepository)
        {
            this._locationRepository = locationRepository;
        }

        public virtual IQueryable<location> GetAllLocations(params Expression<Func<location, object>>[] includeProperties)
        {
            return _locationRepository.Table.IncludeProperties(includeProperties);
        }
    }
}

locationController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using GeoLocationApi.Models;
using GeoLocationApi.Services;
using GeoLocationApi.Infrastructure;

namespace GeoLocationApi.Controllers
{
    [RoutePrefix("api")]
    public class locationController : ApiController
    {
        private readonly IlocationService _locationService;

        public locationController(IlocationService locationService)
        {
            this._locationService = locationService;
        }

        [Route("getlocation")]
        [HttpGet]
        public locationDTO GetLocationDetails()
        {
           var data = _locationService.GetAllLocations().Where(x => x.locationActiveStatus != false);

            return AutoMapperConfiguration.Mapper.Map<locationDTO>(data);

        }
    }
}

IRepository.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using GeoLocationApi.Models;

namespace GeoLocationApi.Services
{
    public partial interface IRepository<T> where T : BaseEntity
    {
        /// <summary>
        /// Get entity by identifier
        /// </summary>
        /// <param name="id">Identifier</param>
        /// <returns>Entity</returns>
        T GetById(object id);

        /// <summary>
        /// Insert entity
        /// </summary>
        /// <param name="entity">Entity</param>
        void Insert(T entity);

        /// <summary>
        /// Insert entities
        /// </summary>
        /// <param name="entities">Entities</param>
        void Insert(IEnumerable<T> entities);

        /// <summary>
        /// Update entity
        /// </summary>
        /// <param name="entity">Entity</param>
        void Update(T entity);

        /// <summary>
        /// Update entities
        /// </summary>
        /// <param name="entities">Entities</param>
        void Update(IEnumerable<T> entities);

        /// <summary>
        /// Delete entity
        /// </summary>
        /// <param name="entity">Entity</param>
        void Delete(T entity);

        /// <summary>
        /// Delete entities
        /// </summary>
        /// <param name="entities">Entities</param>
        void Delete(IEnumerable<T> entities);

        /// <summary>
        /// Gets a table
        /// </summary>
        IQueryable<T> Table { get; }

        /// <summary>
        /// Gets a table with "no tracking" enabled (EF feature) Use it only when you load record(s) only for read-only operations
        /// </summary>
        IQueryable<T> TableNoTracking { get; }


    }
}

locationContext.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;

namespace GeoLocationApi.Models
{
    public class locationContext : DbContext
    {
        public DbSet<location> Location { get; set; } 
    }
}

location.cs

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

namespace GeoLocationApi.Models
{
    public class location : BaseEntity
    {
        public string locationName { get; set; }
        public string locationDescription { get; set; }
        public string locationLongitude { get; set; }
        public string locationLatitutde { get; set; }
        public bool locationActiveStatus { get; set; }
    }
}

当我运行项目时，我在浏览器选项卡中收到有关构造函数的错误。

<Error>
<Message>An error has occurred.</Message>
<ExceptionMessage>
An error occurred when trying to create a controller of type 'locationController'. Make sure that the controller has a parameterless public constructor.
</ExceptionMessage>
<ExceptionType>System.InvalidOperationException</ExceptionType>
<StackTrace>
at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType) at System.Web.Http.Controllers.HttpControllerDescriptor.CreateController(HttpRequestMessage request) at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()
</StackTrace>
<InnerException>
<Message>An error has occurred.</Message>
<ExceptionMessage>
An error occurred during the activation of a particular registration. See the inner exception for details. Registration: Activator = locationController (ReflectionActivator), Services = [GeoLocationApi.Controllers.locationController], Lifetime = Autofac.Core.Lifetime.CurrentScopeLifetime, Sharing = None, Ownership = OwnedByLifetimeScope ---> None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' on type 'GeoLocationApi.Controllers.locationController' can be invoked with the available services and parameters: Cannot resolve parameter 'GeoLocationApi.Services.IlocationService locationService' of constructor 'Void .ctor(GeoLocationApi.Services.IlocationService)'. (See inner exception for details.)
</ExceptionMessage>
<ExceptionType>Autofac.Core.DependencyResolutionException</ExceptionType>
<StackTrace>
at Autofac.Core.Resolving.InstanceLookup.Activate(IEnumerable`1 parameters) at Autofac.Core.Resolving.InstanceLookup.Execute() at Autofac.Core.Resolving.ResolveOperation.GetOrCreateInstance(ISharingLifetimeScope currentOperationScope, IComponentRegistration registration, IEnumerable`1 parameters) at Autofac.Core.Resolving.ResolveOperation.Execute(IComponentRegistration registration, IEnumerable`1 parameters) at Autofac.Core.Lifetime.LifetimeScope.ResolveComponent(IComponentRegistration registration, IEnumerable`1 parameters) at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context, Service service, IEnumerable`1 parameters, Object& instance) at Autofac.ResolutionExtensions.ResolveOptionalService(IComponentContext context, Service service, IEnumerable`1 parameters) at Autofac.ResolutionExtensions.ResolveOptional(IComponentContext context, Type serviceType) at Autofac.Integration.WebApi.AutofacWebApiDependencyScope.GetService(Type serviceType) at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.GetInstanceOrActivator(HttpRequestMessage request, Type controllerType, Func`1& activator) at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)
</StackTrace>
<InnerException>
<Message>An error has occurred.</Message>
<ExceptionMessage>
None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' on type 'GeoLocationApi.Controllers.locationController' can be invoked with the available services and parameters: Cannot resolve parameter 'GeoLocationApi.Services.IlocationService locationService' of constructor 'Void .ctor(GeoLocationApi.Services.IlocationService)'.
</ExceptionMessage>
<ExceptionType>Autofac.Core.DependencyResolutionException</ExceptionType>
<StackTrace>
at Autofac.Core.Activators.Reflection.ReflectionActivator.GetValidConstructorBindings(IComponentContext context, IEnumerable`1 parameters) at Autofac.Core.Activators.Reflection.ReflectionActivator.ActivateInstance(IComponentContext context, IEnumerable`1 parameters) at Autofac.Core.Resolving.InstanceLookup.Activate(IEnumerable`1 parameters)
</StackTrace>
</InnerException>
</InnerException>
</Error>

由于我是Stackoverflow和ASP.NET WEB API的新手，我需要您解释一下这个问题并告诉我它为什么会出现这个错误。

提前致谢，感谢您的帮助。

Answer 1

我认为你错误地注册了navigator.geolocation.getCurrentPosition( function (pos) { var myLatLng = new google.maps.LatLng(parseFloat(pos.coords.latitude), parseFloat(pos.coords.longitude)); this.setCurrentLocationMarker(myLatLng); map.setCenter(myLatLng); }, function (error) { return false; }); setCurrentLocationMarker(latLng) { this.userLat = latLng.lat(); this.userLng = latLng.lng(); this.$scope.$apply(); }，它应该映射到界面，而不是实际类

locationService

Autofac Web API依赖注入问题

1 个答案: