结构图无参数构造函数错误

Question

我正在尝试使用Web API 2设置结构图ver 3.0.5.0.

我已经遵循了这个实现:使用ASP.NET Web API 2.1配置依赖注入

但是,在针对ComplexesController进行攻击时出现此错误:

尝试创建"ComplexesController"类型的控制器时发生错误.确保控制器具有无参数的公共构造函数.

谁能看到我的structuremap配置有什么问题？永远不会调用Create方法.

这是我的实施:

public class StructureMapControllerActivator : IHttpControllerActivator
{
    private readonly IContainer _container;

    public StructureMapControllerActivator(IContainer container)
    {
        if (container == null) throw new ArgumentNullException("container");
        _container = container;
    }

    public IHttpController Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)
    {
        try
        {                
            var scopedContainer = _container.GetNestedContainer();
            scopedContainer.Inject(typeof(HttpRequestMessage), request);
            request.RegisterForDispose(scopedContainer);
            return (IHttpController)scopedContainer.GetInstance(controllerType);
        }
        catch (Exception e)
        {
            // TODO : Logging
            throw e;
        }
    }
}

这个方法在我的创业公司......

public void InitializeContainer()
    {
        // STRUCTURE MAP
        Container container = new Container();
        GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerActivator), new StructureMapControllerActivator(container));

        container.Configure(x => x.For<IForumRepository>().Use<ForumRepository>());
        container.Configure(x => x.For<IComplexRepository>().Use<ComplexRepository>());        
    }

..这是控制器:

 public class ComplexesController : ApiController
{

    private IComplexRepository _repo;

    public ComplexesController(IComplexRepository repo)
    {
        _repo = repo;
    }

    // GET: api/Complexes
    public IList<Complex> GetComplexes()
    {
        var complexes = _repo.GetList();
        return complexes;
    }
    ...

我的完整启动课程

[assembly: OwinStartup(typeof(AngularJSAuthentication.API.Startup))]
namespace AngularJSAuthentication.API
{
  public class Startup
   {
    public void Configuration(IAppBuilder app)
    {
        HttpConfiguration config = new HttpConfiguration();
        WebApiConfig.Register(config);
        app.UseWebApi(config);
    }

  }
}

Answer 1

这里的问题是您使用GlobalConfiguration对象而不是HttpConfiguration对象注册服务激活器.在这种情况下,GlobalConfiguration对象永远不会被使用,因为它被HttpConfiguration对象替换.为了解决您的问题,您应该使用以下内容替换InitializeContainer()方法.

public void InitializeContainer(HttpConfiguration config)
    {
        // STRUCTURE MAP
        Container container = new Container();
        config.Services.Replace(typeof(IHttpControllerActivator), new StructureMapControllerActivator(container));

        container.Configure(x => x.For<IForumRepository>().Use<ForumRepository>());
        container.Configure(x => x.For<IComplexRepository>().Use<ComplexRepository>());        
    }

然后,您应该将HttpConfiguration对象从Startup类传递给新的InitializeContainer()方法.

希望这可以帮助.

-B