Multiple actions were found that match the request in Web Api

https://stackoverflow.com/questions/14534167/multiple-actions-were-found-that-match-the-request-in-web-api

Answer1

Your route map is probably something like this:

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.

Answer2

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)
{
    rturn 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

 Answer3

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) 

For me this worked, but only after changing the order of routes in the route configuration so that the one with action appeared first

https://docs.microsoft.com/en-us/aspnet/web-api/overview/getting-started-with-aspnet-web-api/tutorial-your-first-web-api

 https://www.cnblogs.com/chucklu/p/10283664.html

目前的修改方案是，添加了action

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

这样会导致的问题是，之前可以工作的，现在不工作了

request1 404错误

GET http://localhost/Chuck_WebApi/api/products HTTP/1.1
User-Agent: Fiddler
Host: localhost
Content-Length: 0

request2  404错误

GET http://localhost/Chuck_WebApi/api/product/1 HTTP/1.1
User-Agent: Fiddler
Host: localhost
Content-Length: 0

request1需要修改为

GET http://localhost/Chuck_WebApi/api/products/getallproducts HTTP/1.1
User-Agent: Fiddler
Host: localhost
Content-Length: 0

request2需要修改为

GET http://localhost/Chuck_WebApi/api/products/getproduct/1 HTTP/1.1
User-Agent: Fiddler
Host: localhost
Content-Length: 0