Multiple actions were found that match the request in Web Api

Question

I keep getting this error when I try to have 2 "Get" methods

Multiple actions were found that match the request: webapi

I been looking around at the other similar questions about this on stack but I don't get it.

I have 2 different names and using the "HttpGet" attribute

[HttpGet]
public HttpResponseMessage Summary(MyVm vm)
{
    return null;
}

[HttpGet]
public HttpResponseMessage FullDetails()
{
    return null;
}

score 538 · Accepted Answer · edited Jul 08 '21 at 12:55

538

Your route map is probably something like this in WebApiConfig.cs:

routes.MapHttpRoute(
name: "API Default",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional });

But in order to have multiple actions with the same http method you need to provide webapi with more information via the route like so:

routes.MapHttpRoute(
name: "API Default",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional });

Notice that the routeTemplate now includes an action. Lots more info here: http://www.asp.net/web-api/overview/web-api-routing-and-actions/routing-in-aspnet-web-api

Update:

Alright, now that I think I understand what you are after here is another take at this:

Perhaps you don't need the action url parameter and should describe the contents that you are after in another way. Since you are saying that the methods are returning data from the same entity then just let the parameters do the describing for you.

For example your two methods could be turned into:

public HttpResponseMessage Get()
{
    return null;
}

public HttpResponseMessage Get(MyVm vm)
{
    return null;
}

What kind of data are you passing in the MyVm object? If you are able to just pass variables through the URI, I would suggest going that route. Otherwise, you'll need to send the object in the body of the request and that isn't very HTTP of you when doing a GET (it works though, just use [FromBody] infront of MyVm).

Hopefully this illustrates that you can have multiple GET methods in a single controller without using the action name or even the [HttpGet] attribute.

edited Jul 08 '21 at 12:55

Deepak

125
2
12

answered Jan 26 '13 at 06:48

Jed

8,022
3
19
19

Is there any advantages of doing one way or another? If I do the secondary do I just have to put the Http action on each method? Is that the big draw back? – chobo2 Jan 30 '13 at 18:29
3

Whether one holds an advantage over the other really depends on your project. If you are building a RESTful api, then you'll want to use the HTTP conventions (GET, POST, PUT, DELETE...). In this case the first block of routing code is the way to go but you will want a different controller for every entity that you expose through the api. Based on your method names, I'm guessing this is not the case so use the more descriptive routing. When your route includes the action you will want to explicitly put the http attribute on each method. – Jed Jan 31 '13 at 05:39
but can't you still use the restful conventions even if you use the second method if you just put the right attribute on each method? Well I really can't break it up to a separate entity. I mean it is the same data just less of it. Sure I could just have one get method and always return all the data back and let the client deal with it but if the device is a mobile device you really want to send back as little data as possible otherwise your wasting a person data what can be expensive. – chobo2 Jan 31 '13 at 18:33
1

@chobo2 Why not just use methods that are named accordingly within the controller? GetSummary(MyVm wm) and GetDetails() – Jed Feb 13 '13 at 22:03
Is that not what I was doing in my original post(did not use Get in front but had the attribute on top) – chobo2 Feb 18 '13 at 18:03
1

Thanks for your answer, just helped me figure out why route resolution was not working even though both my actions had different names. I'm really confused as to why isn't just the default behavior (i.e. why does't the default route template in webapiconfig.cs inlcude "{action}")! – Tejas Sharma Oct 11 '13 at 20:06
@TejasSharma I'm glad it helped you out! As to why it's not the default behavior: Web API is RESTful by default and expects the action to be based on the HTTP method of the request (GET/PUT/POST/DELETE). Including the action in the url is more of an RPC schema. – Jed Oct 12 '13 at 16:59
I'd like to add that the routes being updated in the response above are in WebApiConfig.cs and not RouteConfig.cs. It took me a minute to realize this. – Bruno Feb 20 '14 at 20:55
1

@bruno if using areas you can also add 'admin' specific APIs like this in AdminAreaRegistration http://stackoverflow.com/a/9849011/16940 – Simon_Weaver Jul 11 '14 at 05:18

score 83 · Answer 2 · edited Oct 02 '20 at 09:00

Update as of Web API 2.

With this API config in your WebApiConfig.cs file:

public static void Register(HttpConfiguration config)
{
    //// Web API routes
    config.MapHttpAttributeRoutes(); //Don't miss this

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

You can route our controller like this:

[Route("api/ControllerName/Summary")]
[HttpGet]
public HttpResponseMessage Summary(MyVm vm)
{
    return null;
}

[Route("api/ControllerName/FullDetails")]
[HttpGet]
public HttpResponseMessage FullDetails()
{
    return null;
}

Where ControllerName is the name of your controller (without "controller"). This will allow you to get each action with the route detailed above.

For further reading: http://www.asp.net/web-api/overview/web-api-routing-and-actions/attribute-routing-in-web-api-2

I really liked this solution. My default route still the same and I have an "exception" route for the exceptions — Leandro De Mello Fagundes, Jan 13 '17 at 18:12
you can also map the parameters into the url EX: [Route("api/ControllerName/Summary/{vm}")] — nulltron, May 10 '18 at 18:50

score 15 · Answer 3 · edited May 10 '13 at 19:58

In Web API (by default) methods are chosen based on a combination of HTTP method and route values.

MyVm looks like a complex object, read by formatter from the body so you have two identical methods in terms of route data (since neither of them has any parameters from the route) - which makes it impossible for the dispatcher (IHttpActionSelector) to match the appropriate one.

You need to differ them by either querystring or route parameter to resolve ambiguity.

score 14 · Answer 4 · answered Oct 23 '14 at 04:40

14

After a lot of searching the web and trying to find the most suitable form for routing map if have found the following

config.Routes.MapHttpRoute("DefaultApiWithId", "Api/{controller}/{id}", new { id =RouteParameter.Optional }, new { id = @"\d+" });
config.Routes.MapHttpRoute("DefaultApiWithAction", "Api/{controller}/{action}");

These mapping applying to both action name mapping and basic http convention (GET,POST,PUT,DELETE)

answered Oct 23 '14 at 04:40

Moatasem bakri

147
1
4
16

9

For me this worked, but only after changing the order of routes in the route configuration so that the one with action appeared first – Fredrik Stolpe Apr 09 '15 at 14:01
exactly order is important here – A.T. Dec 03 '15 at 17:11

score 12 · Answer 5 · answered Nov 15 '18 at 15:28

This is the answer for everyone who knows everything is correct and has checked 50 times.....

Make sure you are not repeatedly looking at RouteConfig.cs.

The file you want to edit is named WebApiConfig.cs

Also, it should probably look exactly like this:

using System.Web.Http;

namespace My.Epic.Website
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
          config.MapHttpAttributeRoutes();

          // api/Country/WithStates
          config.Routes.MapHttpRoute(
            name: "ControllerAndActionOnly",
            routeTemplate: "api/{controller}/{action}",
            defaults: new { },
            constraints: new { action = @"^[a-zA-Z]+([\s][a-zA-Z]+)*$" });

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

I could have saved myself about 3 hours.

Thanks, you saved me about 3 hours – geedubb Mar 05 '20 at 13:45 — geedubb, Mar 05 '20 at 13:45
Dude. This definitely saved me some hours. Thank you! – Baku Retsu Mar 04 '22 at 19:18 — Baku Retsu, Mar 04 '22 at 19:18

score 5 · Answer 6 · answered Jan 26 '13 at 05:35

It might be possible that your webmethods are being resolved to the same url. Have a look at the following link :-

http://www.asp.net/web-api/overview/web-api-routing-and-actions/routing-in-aspnet-web-api

So, you might need to add your methodname to your routing table.

score 5 · Answer 7 · answered Jan 26 '13 at 14:35

5

Without using actions the options would be:

move one of the methods to a different controller, so that they don't clash.
use just one method that takes the param, and if it's null call the other method from your code.

answered Jan 26 '13 at 14:35

Joanna Derks

4,033
3
26
32

It might be solution, but not optimum one, anyway +1 from my side :) – satish kumar V May 18 '15 at 09:09

score 4 · Answer 8 · answered Mar 31 '18 at 04:03

This solution worked for me.

Please place Route2 first in WebApiConfig. Also Add HttpGet and HttpPost before each method and include controller name and method name in the url.

WebApiConfig =>

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

Controller =>

public class ValuesController : ApiController
{

    [HttpPost]
    public string GetCustomer([FromBody] RequestModel req)
    {
        return "Customer";
    }

    [HttpPost]
    public string GetCustomerList([FromBody] RequestModel req)
    {
        return "Customer List";
    }
}

Url =>

http://localhost:7050/api/Values/GetCustomer

http://localhost:7050/api/Values/GetCustomerList

score 3 · Answer 9 · answered Mar 25 '15 at 22:35

I found that that when I have two Get methods, one parameterless and one with a complex type as a parameter that I got the same error. I solved this by adding a dummy parameter of type int, named Id, as my first parameter, followed by my complex type parameter. I then added the complex type parameter to the route template. The following worked for me.

First get:

public IEnumerable<SearchItem> Get()
{
...
}

Second get:

public IEnumerable<SearchItem> Get(int id, [FromUri] List<string> layers)
{
...
}

WebApiConfig:

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

score 3 · Answer 10 · edited Oct 20 '17 at 08:50

3

It is possible due to using MVC controller instead of Web API controller. Check the namespace in Web API controller it should be as following

using System.Net;
using System.Net.Http;
using System.Web.Http;

If the namespace are as following then it is give above error in web api controller method calling

using System.Web;
using System.Web.Mvc;

edited Oct 20 '17 at 08:50

Pang

9,564
146
81
122

answered Nov 27 '15 at 11:45

Ujwal Khairnar

508
1
4
19

score 2 · Answer 11 · answered Jul 10 '13 at 18:16

2

Please check you have two methods which has the different name and same parameters.

If so please delete any of the method and try.

answered Jul 10 '13 at 18:16

Ramesh

1,692
2
18
37

score 2 · Answer 12 · answered Jun 04 '15 at 13:03

I've stumbled upon this problem while trying to augment my WebAPI controllers with extra actions.

Assume you would have

public IEnumerable<string> Get()
{
    return this.Repository.GetAll();
}

[HttpGet]
public void ReSeed()
{
    // Your custom action here
}

There are now two methods that satisfy the request for /api/controller which triggers the problem described by TS.

I didn't want to add "dummy" parameters to my additional actions so I looked into default actions and came up with:

[ActionName("builtin")]
public IEnumerable<string> Get()
{
    return this.Repository.GetAll();
}

for the first method in combination with the "dual" route binding:

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

config.Routes.MapHttpRoute(
    name: "CustomActionApi",
    routeTemplate: "api/{controller}/{action}");

Note that even though there is no "action" parameter in the first route template apparently you can still configure a default action allowing us to separate the routing of the "normal" WebAPI calls and the calls to the extra action.

score 2 · Answer 13 · answered Mar 12 '19 at 07:01

2

In my Case Everything was right

1) Web Config was configured properly 2) Route prefix and Route attributes were proper

Still i was getting the error. In my Case "Route" attribute (by pressing F12) was point to System.Web.MVc but not System.Web.Http which caused the issue.

answered Mar 12 '19 at 07:01

Hemanth Vatti

85
1
8

This answer helped me a lot! – tvb108108 Jul 12 '19 at 04:05

score 2 · Answer 14 · answered Jul 22 '19 at 19:03

2

You can add [Route("api/[controller]/[action]")] to your controller class.

[Route("api/[controller]/[action]")]
[ApiController]
public class MySuperController : ControllerBase
{
 ...
}

answered Jul 22 '19 at 19:03

emert117

1,268
2
20
38

score 0 · Answer 15 · answered Jun 20 '17 at 15:40

0

I know it is an old question, but sometimes, when you use service resources like from AngularJS to connect to WebAPI, make sure you are using the correct route, other wise this error happens.

answered Jun 20 '17 at 15:40

Suresh Kaushik

77
7

score 0 · Answer 16 · answered Sep 06 '17 at 00:47

Make sure you do NOT decorate your Controller methods for the default GET|PUT|POST|DELETE actions with [HttpPost/Put/Get/Delete] attribute. I had added this attibute to my vanilla Post controller action and it caused a 404.

Hope this helps someone as it can be very frustrating and bring progress to a halt.

score 0 · Answer 17 · edited Jan 15 '19 at 13:07

For example => TestController

        [HttpGet]
        public string TestMethod(int arg0)
        {
            return "";
        }

        [HttpGet]
        public string TestMethod2(string arg0)
        {
            return "";
        }

        [HttpGet]
        public string TestMethod3(int arg0,string arg1)
        {
            return "";
        }

If you can only change WebApiConfig.cs file.

 config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{action}/",
                defaults: null
            );

Thats it :)

And Result :

score 0 · Answer 18 · answered May 15 '19 at 02:36

0

Have you tried like:

[HttpGet("Summary")]
public HttpResponseMessage Summary(MyVm vm)
{
    return null;
}

[HttpGet("FullDetails")]
public HttpResponseMessage FullDetails()
{
    return null;
}

answered May 15 '19 at 02:36

Deepak Shaw

461
3
6

4

This will not compile in non-.NET Core projects, as the `HttpGet` attribute does not have a constructor that accepts a string argument. – Hoppeduppeanut May 15 '19 at 03:05

Multiple actions were found that match the request in Web Api

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