No action was found on the controller 'User' that matches the name 'Name'

Question

I have two action method in my controller.

[RoutePrefix("user")]
public class UserController: ApiController
{
    [HttpGet]
    public IEnumerable<User> Get()
    {
        return new User.GetUsers();
    }

    [Route("{name}")]
    [HttpGet]
    public IEnumerable<User> GetByName(string name)
    {
        return new User.GetUsers(name);
    }
}

Below is my route config file

config.Routes.MapHttpRoute(
    name: "DefaultApi",
    routeTemplate: "{controller}/{action}/{id}",
    defaults: new { controller = "user", id = RouteParameter.Optional }
    );
config.Routes.MapHttpRoute(
    name: "DefaultApiGet",
    routeTemplate: "{controller}/{id}",
    defaults: new { action = "Get", id= RouteParameter.Optional },
    constraints: new { httpMethod = new HttpMethodConstraint(HttpMethod.Get) }
    );

I am calling the following

localhost/User - - Working
localhost/User/Jane -- Not working throwing error.

I am not sure what is wrong with the API.

Answer 1

you need to enable attribute routing config.MapHttpAttributeRoutes() before convention-based routes

And also update controller. Try not to mix convention-based and attribute routes in the same controller

[RoutePrefix("user")]
public class UserController: ApiController
{
    //GET user
    [Route("")]
    [HttpGet]
    public IEnumerable<User> Get() { ... }

    //GET user/Jane
    [Route("{name}")]
    [HttpGet]
    public IEnumerable<User> GetByName(string name) { ... }
}