c# - 在 Web API 和 OWIN 中使用简单注入(inject)器

Question

我遇到了与 described here 相同的问题我的设置几乎是identical to this这实际上是基于 this guide .当我在我的 Controller 中访问一个方法时，我得到了这个

An error occurred when trying to create a controller of type 'TestController'. Make sure that the controller has a parameterless public constructor.

这是堆栈跟踪

at System.Web.Http.Dispatcher.DefaultHttpControllerActivator
  .Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, 
     Type controllerType)\r\n   
at System.Web.Http.Controllers.HttpControllerDescriptor
  .CreateController(HttpRequestMessage request)\r\n   
at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()

这是内部异常的堆栈跟踪

at System.Linq.Expressions.Expression.New(Type type)\r\n  
at System.Web.Http.Internal.TypeActivator.Create[TBase](Type instanceType)\r\n   
at System.Web.Http.Dispatcher.DefaultHttpControllerActivator
   .GetInstanceOrActivator(HttpRequestMessage request, Type controllerType, Func`1& activator)\r\n   
at System.Web.Http.Dispatcher.DefaultHttpControllerActivator
   .Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)

这是我的 Controller 的样子

public class TestController : ApiController
{
    private readonly ITestRepo _repo;
    public TestController(ITestRepo repo)
    {
        _repo = repo;
    }

    public IEnumerable<string> Get()
    {
        return new string[] { "value1", "value2" };
    }

    public string Get(int id)
    {
        return _repo.GetId(id);
    }
}

下面是我如何设置 Simple Injector

 public class Startup
 {        
   public void Configuration(IAppBuilder app)
   {
      // Create the container as usual.
      var container = new Container();
      // Register your types, for instance using the RegisterWebApiRequest
      // extension from the integration package:       
      container.RegisterWebApiRequest<ITestRepo, TestRepo>(); 

     container.RegisterWebApiControllers(GlobalConfiguration.Configuration);

      container.Verify();

      GlobalConfiguration.Configuration.DependencyResolver =
            new SimpleInjectorWebApiDependencyResolver(container);

      //
      ConfigureOAuth(app, container);

      var config = new HttpConfiguration();
      WebApiConfig.Register(config);
      app.UseWebApi(config);
   }
}

Answer 1

我遇到了同样的问题，但使用的是 UnityDependencyResolver。但我认为它也应该适用于 SimpleInjectorWebApiDependencyResolver。尝试像这样注册您的解析器(作为 HttpConfiguration 的属性):

public void Configuration(IAppBuilder app)
{
    var container = GetContainer(); // Initialise container

    HttpConfiguration config = new HttpConfiguration
    {
        DependencyResolver = new SimpleInjectorWebApiDependencyResolver(container);
    };

    WebApiConfig.Register(config);
    app.UseWebApi(config);
}