How to use Query String parameters in the ASP.NET MVC API

I gess your mistake is that you using RoutePrefix on controller class with Route on method.

If you want to call url like you show you should define your controller like this:

[RoutePrefix("web/api/users")]
public class UsersController : BaseController
{
    [HttpGet]
    public Response<List<UserDTO>> Get(string q, string ex)

Try This :

`[RoutePrefix("web/api")]
public class UsersController : BaseController
{
    [Route("users/{q}/{ex}")]
    [HttpGet]
    public Response<List<UserDTO>> Get(string q, string ex)`

and just call api like : web/api/users/text1/text2

You can add custom routes

config.Routes.MapHttpRoute(
    name: "NameOfRoute",
    routeTemplate: "web/{controller}/{action}?q={q}&ex={ex}",
    defaults: new { controller = "controller-name", action = "action-name", 
        q = RouteParameter.Optional, ex= RouteParameter.Optional }
    );

First of all, in order to be able to have multiple GET methods in the same controller, you must add your custom routes:

        config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{action}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );

Then, in your controlller you need to mark the parameter as FromUri in order to tell the method to expect the parameter from the URI. This way, you will be able to call the method the following way:

/web/api/users/Get?q="your string1"&ex="ex"

public Response<List<UserDTO>> Get([FromUri]string q, [FromUri]string ex)

If this is the only GET method, you may skip the part with mapping custom routes.

Hope this helps.

Best of luck!