Url.Link throws Not Implemented exception in Web Api 2

Question

I have the following controller method :

 [Authorize]
    public IHttpActionResult Post(AlertDataModel model)
    {
        var userID = this.User.Identity.GetUserId();
        var alert = new Alert
        {
            Content = model.Content,
            ExpirationDate = DateTime.Now.AddDays(5),
            UserId = userID
        };

        this.Data.Alerts.Add(alert);
        this.Data.SaveChanges();

        var returnedAlert = new AlertDataModel
        {
            ID = alert.ID,
            Content = alert.Content
        };
        var link = Url.Link(routeName: "DefaultApi", routeValues: new { id = alert.ID });
        var uri = new Uri(link);
        return Created(uri, returnedAlert);
    }

But i got NotImplementedException on this row :

var link = Url.Link(routeName: "DefaultApi", routeValues: new { id = alert.ID });

Here is the full error:

Message: "An error has occurred."
ExceptionMessage: "The method or operation is not implemented."
ExceptionType: "System.NotImplementedException"
StackTrace: " at System.Web.HttpContextBase.get_Response()\ \ at System.Web.UI.Util.GetUrlWithApplicationPath(HttpContextBase context, String url)\ \ at System.Web.Routing.RouteCollection.NormalizeVirtualPath(RequestContext requestContext, String virtualPath)\ \ at System.Web.Routing.RouteCollection.GetVirtualPath(RequestContext requestContext, String name, RouteValueDictionary values)\ \ at System.Web.Http.WebHost.Routing.HostedHttpRouteCollection.GetVirtualPath(HttpRequestMessage request, String name, IDictionary`2 values)\ \ at System.Web.Http.Routing.UrlHelper.GetVirtualPath(HttpRequestMessage request, String routeName, IDictionary`2 routeValues)\ \ at System.Web.Http.Routing.UrlHelper.Route(String routeName, IDictionary`2 routeValues)\ \ at System.Web.Http.Routing.UrlHelper.Link(String routeName, IDictionary`2 routeValues)\ \ at System.Web.Http.Routing.UrlHelper.Link(String routeName, Object routeValues)\ \ at Exam.WebAPI.Controllers.AlertsController.Post(AlertDataModel model) in c:\\Users\\Kiril\\Desktop\\New folder\\Exam.WebAPI\\Controllers\\AlertsController.cs:line 63\ \ at lambda_method(Closure , Object , Object[] )\ \ at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)\ \ at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)\ \ at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)\ \ --- End of stack trace from previous location where exception was thrown ---\ \ at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\ \ at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\ \ at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\ \ --- End of stack trace from previous location where exception was thrown ---\ \ at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\ \ at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\ \ at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\ \ --- End of stack trace from previous location where exception was thrown ---\ \ at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\ \ at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\ \ at System.Web.Http.Filters.AuthorizationFilterAttribute.<ExecuteAuthorizationFilterAsyncCore>d__2.MoveNext()\ \ --- End of stack trace from previous location where exception was thrown ---\ \ at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\ \ at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\ \ at System.Web.Http.Controllers.AuthenticationFilterResult.<ExecuteAsync>d__0.MoveNext()\ \ --- End of stack trace from previous location where exception was thrown ---\ \ at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\ \ at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\ \ at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"

I have the following routing:

config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

I tried to decompile the code and the error was thrown in ReflectedHttpActionDescriptor.ExecuteAsync Method.

Any ideas?

Answer 1

If you're using OWIN, ensure that you're using a new HttpConfiguration object in the Startup Configuration method:

public class Startup
{
    public static OAuthAuthorizationServerOptions OAuthOptions { get; private set; }
    public static string PublicClientId { get; private set; }

    public void Configuration(IAppBuilder app)
    {
        var config = new HttpConfiguration();

        ConfigureWebApi(config);

        ConfigureAuth(app);

        app.UseWebApi(config);
    }

    ...

}

It took me several hours to figure out that you shouldn't use a reference to GlobalConfiguration when using OWIN:

GlobalConfiguration.Configure(WebApiConfig.Register);