ASP.NET Web API 2 override inherited attribute route action multiple actions found

Question

To keep an overview in my Web API, I am using a base controller that contains some basic actions that most of my other controllers use. (E.g. Post([FromBody]JObject newFields) to add a new item.)

In my project, I have attribute routing enabled. So my base controller looks somewhat like the following:

public class BaseController<T> : ApiController where T : ObjectBase, new()
{
    [Route("")]
    [ResponseType(typeof(ObjectBase))]
    public virtual IHttpActionResult Post([FromBody]JObject newFields)
    {
        // Post logic
        return Ok();
    }
}

I am inheriting this base controller in most of the other controllers in my project.

Now for my problem:

In one of my controllers, I want to override this method, because some of the creation logic is different.

This is an example of how I am trying to accomplish that functionality:

[RoutePrefix("api/Users")]
public class UsersController : BaseController<UserObject>
{
    [Route("")]
    [ResponseType(typeof(ObjectBase))]
    public override IHttpActionResult Post([FromBody]JObject newFields)
    {
        // Overridden post logic
        return Ok();
    }
}

However, when I now send a POST request to https://url/api/Users, I get the following error response:

Message:

An error has occurred.

ExceptionMessage:

Multiple actions were found that match the request:

Post on type WebAPI.Controllers.UsersController

Post on type WebAPI.Controllers.UsersController

ExceptionType:

System.InvalidOperationException

StackTrace:

at System.Web.Http.Controllers.ApiControllerActionSelector.ActionSelectorCacheItem.SelectAction(HttpControllerContext controllerContext)

at System.Web.Http.ApiController.ExecuteAsync(HttpControllerContext controllerContext, CancellationToken cancellationToken)

at System.Web.Http.Dispatcher.HttpControllerDispatcher.d__1.MoveNext()

Anyone who can help me solve this problem?

Thanks in advance!

DylanVB DylanVB · Accepted Answer · 2018-06-08T06:03:14

After trying a lot of things, I finally found a most simple solution. Seems like I just had to remove the attributes in my derived class.

So to follow the example I used in my original post, the UsersController now looks like this:

[RoutePrefix("api/Users")]
public class UsersController : BaseController<UserObject>
{
    public override IHttpActionResult Post([FromBody]JObject newFields)
    {
        // Overridden post logic
        return Ok();
    }
}

ASP.NET Web API 2 override inherited attribute route action multiple actions found

1 Answers