ASP.NET Core routing based on query parameters

Question

I'm migrating old (bad) code for ASP.NET Web API (.NET Framework 4.5) to ASP.NET Core 6. I must maintain backward compatibility.

There are two methods on controller that are different only by arguments:

public IEnumerable<string> Get([FromUri] string tags, [FromUri] string counter) {...}
public IEnumerable<string> Get([FromUri] string folders, [FromUri] string tags, [FromUri] string counter) {...}

The routing is typical (nothing special):

config.Routes.MapHttpRoute("default",
  "api/{controller}/{id}",
  new { id = RouteParameter.Optional },
  null,
  null });

This works in .NET Framework 4.5, the following requests are routed correctly:

/api/RTData2?tags=0,1,2&counter=762
/api/RTData2?folders=0,1,2&tags=11,12,17&counter=133

How do I make that work with ASP.NET Core? (the client/web side is out of my touch).

Thank you in advance.

The only relevant information I was able to find: Query parameter routing with asp .net core

But that is not really my case.

Answer 1

you have to actions with the same name "get", maybe you need to add action name to separate them, something like this

[NonAction]
private IEnumerable<string> Get(string tags, string counter) {...}

[HttpGet("~/api/RTData2")] 
public IEnumerable<string> Get(string tags,  string counter, string folders  ) {

if(string.IsNullOrEmpty(folders)) return Get(tags,counter);
...your usual code

}

routing doesn't check how many query string parameters you url has. It will call the action without any parameters as well.