How to pass multiple parameters to a get method in ASP.NET Core

Question

How can I pass in multiple parameters to Get methods in an MVC 6 controller. For example I want to be able to have something like the following.

[Route(\"api         


        

Answer 1

To add some more detail about the overloading that you asked about in your comment after another answer, here is a summary. The comments in the ApiController show which action will be called with each GET query:

public class ValuesController : ApiController
{
    // EXPLANATION: See the view for the buttons which call these WebApi actions. For WebApi controllers, 
    //          there can only be one action for a given HTTP verb (GET, POST, etc) which has the same method signature, (even if the param names differ) so
    //          you can't have Get(string height) and Get(string width), but you can have Get(int height) and Get(string width).
    //          It isn't a particularly good idea to do that, but it is true. The key names in the query string must match the
    //          parameter names in the action, and the match is NOT case sensitive. This demo app allows you to test each of these
    //          rules, as follows:
    // 
    // When you send an HTTP GET request with no parameters (/api/values) then the Get() action will be called.
    // When you send an HTTP GET request with a height parameter (/api/values?height=5) then the Get(int height) action will be called.
    // When you send an HTTP GET request with a width parameter (/api/values?width=8) then the Get(string width) action will be called.
    // When you send an HTTP GET request with height and width parameters (/api/values?height=3&width=7) then the 
    //          Get(string height, string width) action will be called.
    // When you send an HTTP GET request with a depth parameter (/api/values?depth=2) then the Get() action will be called
    //          and the depth parameter will be obtained from Request.GetQueryNameValuePairs().
    // When you send an HTTP GET request with height and depth parameters (/api/values?height=4&depth=5) then the Get(int height) 
    //          action will be called, and the depth parameter would need to be obtained from Request.GetQueryNameValuePairs().
    // When you send an HTTP GET request with width and depth parameters (/api/values?width=3&depth=5) then the Get(string width) 
    //          action will be called, and the depth parameter would need to be obtained from Request.GetQueryNameValuePairs().
    // When you send an HTTP GET request with height, width and depth parameters (/api/values?height=7&width=2&depth=9) then the 
    //          Get(string height, string width) action will be called, and the depth parameter would need to be obtained from 
    //          Request.GetQueryNameValuePairs().
    // When you send an HTTP GET request with a width parameter, but with the first letter of the parameter capitalized (/api/values?Width=8) 
    //          then the Get(string width) action will be called because the case does NOT matter.
    // NOTE: If you were to uncomment the Get(string height) action below, then you would get an error about there already being  
    //          a member named Get with the same parameter types. The same goes for Get(int id).
    //
    // ANOTHER NOTE: Using the nullable operator (e.g. string? paramName) you can make optional parameters. It would work better to
    //          demonstrate this in another ApiController, since using nullable params and having a lot of signatures is a recipe
    //          for confusion.

    // GET api/values
    public IEnumerable Get()
    {
        return Request.GetQueryNameValuePairs().Select(pair => "Get() => " + pair.Key + ": " + pair.Value);
        //return new string[] { "value1", "value2" };
    }

    //// GET api/values/5
    //public IEnumerable Get(int id)
    //{
    //    return new string[] { "Get(height) => height: " + id };
    //}

    // GET api/values?height=5
    public IEnumerable Get(int height) // int id)
    {
        return new string[] { "Get(height) => height: " + height };
    }

    // GET api/values?height=3
    public IEnumerable Get(string height)
    {
        return new string[] { "Get(height) => height: " + height };
    }

    //// GET api/values?width=3
    //public IEnumerable Get(string width)
    //{
    //    return new string[] { "Get(width) => width: " + width };
    //}

    // GET api/values?height=4&width=3
    public IEnumerable Get(string height, string width)
    {
        return new string[] { "Get(height, width) => height: " + height + ", width: " + width };
    }
}

You would only need a single route for this, in case you wondered:

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

and you could test it all with this MVC view, or something simlar. Yes, I know you aren't supposed to mix JavaScript with markup and I'm not using bootstrap like you would normally, but this is for demo purposes only.

    
Multiple parameters test
    
Click a link below, which will send an HTTP GET request with parameters to a WebAPI controller.



    Pass Nothing
    Pass Height of 5
    Pass Width of 8
    Pass Height of 3 and Width of 7
    Pass Depth of 2
    Pass Height of 4 and Depth of 5
    Pass Width of 3 and Depth of 5
    Pass Height of 7, Width of 2 and Depth of 9
    Pass Height of 7, Width of 2 and Depth of 9
    Pass Width of 8, but with Pascal case