How to get RouteData inside a .net core middleware?

Question

I am working on a .net core app. I am trying to access route data in a middleware but it always returns null.

Here is the controller base route

[Route("User/{UserId}/Quote")]
    public class QuoteController : ControllerBase

My objective is to try to get UserId inside middleware which I am using it for authentication somewhere else. My question is why the GetRouteData() call always return null?

Applejack

If you do this before UseMvc then I don't think you will have access to the routing. – Waitabit

what is strange is that if I put code after UseMvc(), it does not even get to this line. – Applejack

I have the exact same experience as @Applejack – Tendency

Answer 1

Route data is set by the MVC middleware which comes into picture further down the stream. You have to move the context.GetRouteData() call to the line after the await next call to access the route data.

See the picture at https://mcmap.net/q/134949/-asp-net-core-middleware-vs-filters for reference.

what is strange is that if I put code after UseMvc(), it does not even get to this line

Once MVC middleware handles the request it sends the response back to the client and doesnt handle the control to middleware next in the pipeline.

Heredity