Prepend a custom parameter before {controller} in ASP.NET WebApi route

Question

I want to create a route template for Owin WebApi like this:

cfg.Routes.MapHttpRoute(
 "API Default", "{myparam}/{controller}/{action}",
 new { id = RouteParameter.Optional });

Because I have controllers defined that need a parameter before the controller selection.

I have tried to remove the parameter and set it into RoutePrefixAttribute on controller but it doesn't work.

{controller} must be the first dynamic parameter of the route?

Answer 1

I would use some form of attribute based routing to go to different controllers based on {myparam}.

First controller:

[Route("param1/customer/{id}")] public IEnumerable<Order> GetOrdersByCustomer(int id) { ... }

Second controller:

[Route("param2/customer/{id}")] public IEnumerable<Order> GetOrdersByCustomer(int id) { ... }

More information can be found here: Attribute Based WebAPI Routing

• Mauro Destro: Sorry but {myparam} is not known at compile time, it's dynamic (like a category name, but it's not like this).
• Trisk: I would take a look here then, routing with optional first parameter

Answer 2

Delete RoutePrefix attribute and set the first parameter dynamic in your action Route attribute like the example below:

[HttpGet, Route("{myparam}/books/{bookId:int:min(1)}")]
public HttpResponseMessage Get(string myparam, int bookId)
{
...
}

• Ken Netherland: You didn't answer question. How do you configure so it works.