Why isn't my C# .Net Core Rest API route finding my method?

Question

I am working on an API. I have an "AbstractController.cs" and I am having difficulties calling a GET with two parameters.

[Route("api/[controller]")]
[ApiController]
public class AbstractController : ControllerBase
{
    // GET: api/Abstract
    [HttpGet]
    public IEnumerable<string> Get()
    {
        return new string[] { "missing implementation" };
    }

Going to https://localhost:44363/api/abstract/ generates this. ["missing implementation"] Awesome!

Now I need to make the Get method that passes in a show year, and code to a SQL query. Easy enough?

// GET: api/Abstract?ShowYear=2019&ShowCode=248621
    [Route("api/{controller}/{ShowYear}/{ShowCode}")]
    [HttpGet]
    public Abstract Get(int ShowYear, int ShowCode) // GetAbstractByYearAndSHCode
    {
        string x = "";
        return new Abstract();
    }

No matter what I do I can't get this method to breakpoint/enter execution! I'm guessing it's a routing issue, but I've tried most tenable ways of calling the endpoint.

Now I check the MS Documentation like any self-respecting-learning-programmer would. https://learn.microsoft.com/en-us/aspnet/core/mvc/controllers/routing?view=aspnetcore-3.1

Endpoint routing in ASP.NET Core 3.0 and later:

Doesn't have a concept of routes. Doesn't provide ordering guarantees for the execution of extensibility, all endpoints are processed at once.

GULP Sounds scary.

I haven't touched my middleware at this point.

All examples I've looked at don't have my "MapControllers();" method in their Startup.cs. This is because it's new to .NET Core 3.0/3.1 The method: "Adds endpoints for controller actions to the IEndpointRouteBuilder without specifying any routes."

OK, so do I have to manually specify the route here still? I did this, and it sorta works.

Well, it breakpoints in the startup.cs now when I go to https://localhost:44363/api/abstract/2019/287

Wait, it's not doing ANYTHING with my controller code! Why?

The following (also above) code ends up declaring as a null in the startup.cs

                    var controller = context.Request.RouteValues["Abstract"];

Hoping to learn what I'm doing wrong.

MapGet("/api/abstract/{showYear}/{showCode}", ...);

Isn't this code responsible for mapping that route with the controller named AbstractController.cs in my Controllers folder? Not hitting any breakpoints.

Edit: Reading through this which compares the differences in the Startup.cs from .Net Core 2, 2.2, MVC projects vs 3.0 I have a good feeling reading all of this, I will find the issue. https://andrewlock.net/comparing-startup-between-the-asp-net-core-3-templates/ Edit.. nevermind didn't find a resolution.

Edit 2:

Completely commenting out this troublesome code in startup.cs:

endpoints.MapGet("/api/abstract/{showYear}/{showCode}", async context =>
            {
                var controller = context.Request.RouteValues["Abstract"];

                var showYear = context.Request.RouteValues["showYear"];
                var showCode = context.Request.RouteValues["showCode"]; // just an example.
                //await context.Response.WriteAsync($"Hello {showYear} is your year, {showCode} for the code!");
                //GetAbstractByYearAndSHCode();
            });
            
            endpoints.MapGet("/api/abstract/{showYear}", async context =>
            {
                var name = context.Request.RouteValues["name"];
                await context.Response.WriteAsync($"Hello {name}!");
            });

Resolves my issue of not being able to reach the controller.

https://localhost:44363/api/abstract/2019 hits, and the id value is 2019. Great. https://i.sstatic.net/Rcoj6.png the output looks great.

I am still not able to use > 1 parameter. How do I simply use the Year, and ShowCode paramaters? What's the syntax? https://localhost:44363/api/abstract/2019

If you create a new project right now in .NC3.1 the default WeatherForecastController.cs value is: [Route("[controller]")] — Dont
– Dont, Commented Jul 12, 2020 at 17:58
Interesting. I thought I'd only ever seen it with curlies. Speaking of starting over; does it work with your new project? — Caius Jard
– Caius Jard, Commented Jul 12, 2020 at 18:00
What do you mean starting over? Let me see. i.imgur.com/UoBJ3ut.png here is the controller, freshly generated. i.imgur.com/BX8WVwc.png — Dont
– Dont, Commented Jul 12, 2020 at 18:03
That new project you've made; does it work? Press play, open postman, add the url, hit send request- does it call the action? — Caius Jard
– Caius Jard, Commented Jul 12, 2020 at 18:06
i.imgur.com/OwEp7p5.png Yes. Just how it works in the original one actually. Yes. — Dont
– Dont, Commented Jul 12, 2020 at 18:07

Legacy Code · Accepted Answer · 2020-07-12 18:49:00Z

1

Just add the parameters to your attribute


[HttpGet("{ShowYear}/{ShowCode}")]

answered Jul 12, 2020 at 18:49

Legacy Code

7707 silver badges12 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Legacy Code Over a year ago

You don’t need the Route attribute though.

Durga Prasad · Accepted Answer · 2020-07-12 19:14:49Z

1

The "api/abstract" route is already used by the first method. You cannot use it again for other actions. Create a new one as shown inline.

[HttpGet("{GetAbstractByYearAndSHCode}",Name = "GetAbstractByYearAndSHCode")]
public Abstract Get(int ShowYear, int ShowCode) // GetAbstractByYearAndSHCode
{
    string x = "";
    return new Abstract();
}

And call the url as shown:

https://localhost/api/abstract/GetAbstractByYearAndSHCode?ShowYear=1&ShowCode=5

edited Jul 12, 2020 at 19:14

answered Jul 12, 2020 at 18:59

Durga Prasad

1,00912 silver badges21 bronze badges

2 Comments

Dont Over a year ago

Going to localhost:44363/api/abstract/2019/248619 prints beautiful json. After changing the attributes as such: i.imgur.com/wbMZxmW.png and navigating to localhost:44363/api/abstract/GetAbstractByYearAndSHCode?ShowYear=2019&ShowCode=248619 I do not return any json. It takes a while, then 404s. I am assuming the "Name" property (GetAbstractByYearAndSHCode) in the HttpGet attribute is the web method name in REST.

Durga Prasad Over a year ago

updated the answer as per the requirement in snippet. You can get rid of the route attribute. It is no longer required. The get attribute route is not proper in the snippet.

Collectives™ on Stack Overflow

Why isn't my C# .Net Core Rest API route finding my method?

2 Answers 2

1 Comment

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related